If r(t) is the position vector for a smooth curve C, and Î (t), Ñ(t), and B(t) are unit tangent vector, principal unit normal vector, and binormal unit vector, respectively, then (1) B(t) · Î(t) = 0, (2) Þ(t) · B(t) = 0, (3) ÎN(t) · (B(t) – 5ÊN(t)) = |ÎN(t)| |B(t) - 5ÊN(t)| cos(π/2) = 0 and (4) Þ(t) x Î (t) = B(t).
(1) Since B(t) is the cross product of Î(t) and Ñ(t), it is perpendicular to both Î(t) and Ñ(t). Therefore, B(t) · Î(t) = 0.
(2) Þ(t) is the derivative of r(t), and B(t) is defined as the cross product of Î(t) and Ñ(t). Therefore, Þ(t) and B(t) are both orthogonal to Î(t). Hence, Þ(t) · B(t) = 0.
(3) ÎN(t) is the cross product of Î(t) and Ñ(t), and B(t) is also the cross product of Î(t) and Ñ(t). Therefore, B(t) - 5ÊN(t) is parallel to ÎN(t). Hence, ÎN(t) · (B(t) - 5ÊN(t)) = |ÎN(t)| |B(t) - 5ÊN(t)| cos(π/2) = 0.
(4) The cross product of two vectors is orthogonal to both of the vectors. Therefore, Þ(t) x Î(t) is orthogonal to both Þ(t) and Î(t), and hence it is parallel to Ñ(t). Therefore, Þ(t) x Î(t) is equal to B(t). So the answer is B.
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En una progresión aritmética sabemos que a2 =1 y a5 =7. Halla el término general y los términos a8 , a15 y a20
The general rule of the arithmetic sequence is given as follows:
[tex]a_n = -1 + 2(n - 1)[/tex]
The terms are given as follows:
[tex]a_8 = 13[/tex][tex]a_{15} = 27[/tex][tex]a_{20} = 37[/tex]What is an arithmetic sequence?An arithmetic sequence is a sequence of values in which the difference between consecutive terms is constant and is called common difference d.
The nth term of an arithmetic sequence is given by the following rule:
[tex]a_n = a_1 + (n - 1)d[/tex]
The difference between the 3 terms is of 6, hence the common difference is given as follows:
3d = 6
d = 2.
As the 2nd term is of 1, the first term is of:
[tex]a_1 = 1 - 2 = -1[/tex]
Hence the rule is given as follows:
[tex]a_n = -1 + 2(n - 1)[/tex]
The terms are given as follows:
[tex]a_8 = -1 + 2 \times 7 = 13[/tex][tex]a_{15} = -1 + 2 \times 14 = 27[/tex][tex]a_{20} = -1 + 2 \times 19 = 37[/tex]More can be learned about arithmetic sequences at https://brainly.com/question/30544915
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determine whether the number described is a statistic or a parameter. in a survery of hospital employees, feel that they are overworked.
In a survery of hospital employees here it is parameter or statistic data is given in Question
Parameters are numeric values that characterize the population as a whole. A statistic is a number that describes the characteristics of a sample.
For example, median income in the United States is a demographic parameter. Conversely, the median income for the US sample is a sample statistic. Both values represent median income, but one is a parameter to the statistic. Easy to remember parameters and stats! Both are summary values that describe the group and have a convenient mnemonic device to remind you which group is being described. Notice their initials.
Parameter = Population
Statistics = Sample
A population is the entire group of people, things, animals, trades, etc. that are being studied. A sample is part of a population.
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During an experiment, the temperature of a mixture changes from 121 1/4 °F to 15 3/5 °F. What is the percent of increase in the temperature of the mixture? Enter your answer in the box as a percent rounded to the nearest hundredth.
The percentage decrease in the temperature is 87.13 %.
What is a percentage?The percentage formula is dividing the required value by the total value and multiplying by 100.
Example:
Required percentage value = a
total value = b
Percentage = a/b x 100
Example:
50% = 50/100 = 1/2
25% = 25/100 = 1/4
20% = 20/100 = 1/5
10% = 10/100 = 1/10
We have,
The temperature of a mixture changes from 121(1/4)°F to 15(3/5)°F.
This means,
Initial temperature = 121(1/4) = 485/4
Final temperature = 15(3/5) = 78/5
The change in temperature.
= 78/5 - 485/4
= (312 - 2425)/20
= 2113/20
= - 105(13/20)
This means,
There is a decrease in temperature.
Now,
The percentage decreased.
= 105(13/20) / (485/4) x 100
= (2113/20) / (485/4) x 100
= 2113/20 x 4/485 x 100
= 2113/2425 x 100
= 87.13%
Thus,
The percentage decrease in the temperature is 87.13 %.
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(x - 5)² +15=143
Find x
The solution is, the value of x = 5+ 8√2, 5- 8√2
What is simplification?Simplify simply means to make it simple. In mathematics, simply or simplification is reducing the expression/fraction/problem in a simpler form. It makes the problem easy with calculations and solving.
here, we have,
given that,
(x - 5)² +15=143
we know, (a-b)^2 = a^2 -2ab + b^2
so, we get,
x^2 - 10x + 25+15 = 143
or, x^2 -10x -103 = 0
now, solving we get,
x = 5+ 8√2, 5- 8√2
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A plane left New York at 3:30pm EST and arrived in Los Angeles at 4:15pm PST. How long did the flight take?
The flight takes a total of 3 hours 45 minutes
How to determine how long did the flight take?From the question, we have the following parameters that can be used in our computation:
Inital time = 3:30 pm EST
Final time = 4:15 pm PST
When converted, we have
Inital time = 12:30 pm PST
Final time = 4:15 pm PST
So, we have
Difference = 4:15 pm PST - 12:30 pm PST
Evaluate the difference
Difference = 3 hours 45 minutes
Hence, the diration is 3 hours 45 minutes
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Find the volume common to two spheres, each with radius r, if the distance between their centers is r/2.
(given information: A cap of a sphere with radius r = 5 and height h = 2.)
The common volume of the two spheres is 5πr³/6. Since the two spheres are identical, the volume of the common portion is twice the volume of the spherical cap.
Since the distance between the centers of the two spheres is r/2, a cross-section of the two spheres and the plane perpendicular to their centers of symmetry will form an isosceles triangle with height h=r/2 and base 2√(r²-(r/2)²). The intersection of the two spheres will be a spherical cap with height h and radius r. The volume of this spherical cap is
V_cap = (1/3)π[tex]h^2[/tex](3r-h).
Since the two spheres are identical, the volume of the common portion is twice the volume of the spherical cap, so
V_common = 2V_cap = (2/3)π[tex]h^2[/tex](3r-h) = (5/6)πr³.Substituting h=r/2, we get
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Jaxson works in a department store selling clothing. He makes a guaranteed salary of $250 per week, but is paid a commission on top of his base salary equal to 15% of his total sales for the week. How much would Jaxson make in a week in which he made $1800 in sales? How much would Jaxson make in a week if he made
�
x dollars in sales?
Answers: Base salary 520:
When selling for X:0.15
Total sales:250+0.15 or 0.15+250
Answer:
Step-by-step explanation:
250 per week base
15%of 1800 he made is = 270
270+250 =520
He made 520$ in the week he made 1800$ in sales
Jaxson's salary is a combination of a fixed $250 plus 15% commission on his weekly sales. For $1800 in sales, he will earn $520. If the sales amount is x dollars, then he will earn $250 + 0.15*x dollars in a week.
Explanation:Jaxson's income consists of a guaranteed base salary of $250 per week and a commission of 15% on his total weekly sales. If Jaxson made $1800 in sales in a week, his total income for the week would be his base salary plus his commission i.e., $250 + 0.15*$1800 = $520.
Similarly, if Jaxson made x dollars in sales in a week, his total income for that week would be his base salary plus his commission on the sales i.e., $250 + 0.15*x dollars.
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eighty-two percent of all women who submit to pregnancy tests are pregnant. a new pregnancy test gives a false positive result with probability 0.02 and a correct positive result with probability 0.95. define the events: p: {a woman is pregnant} and : {the pregnancy test is positive}. a)
The probability that a woman is actually pregnant given that the test is positive is 0.974 (or 97.4%).
a) To find the probability that a woman is actually pregnant given that the test is positive, we can use Bayes' theorem:
P(p|+) = P(+|p) P(p) / P (+)
where P(p) is the prior probability of a woman being pregnant (which is 0.82), P (+) is the probability of a positive test result, and P(+|p) is the conditional probability of a positive test result given that the woman is pregnant.
We are given that the test has a false positive rate of 0.02, which means that P(+|~p) = 0.02 (where ~p denotes "not pregnant"). We are also given that the test has a correct positive rate of 0.95, which means that P (+|p) = 0.95. Therefore, we can calculate:
P (+) = P(+|p) P(p) + P(+|~p) P(~p)
= 0.95 * 0.82 + 0.02 * (1 - 0.82)
= 0.802
Substituting into Bayes' theorem, we get:
P(p|+) = 0.95 * 0.82 / 0.802
= 0.974
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Jason and Caleb shared the profits from their lemonade stand in a ratio of 2:3. if they earned $40 all together how much money did Jason make?
Answer: Jason made $16
Step-by-step explanation:
Start by using the ratio of 2:3 to find the fraction of the total profit that Jason earned: Jason's share: 2/(2+3) = 2/5
Caleb's share: 3/(2+3) = 3/5
We can then use this fraction to calculate how much money Jason made:
Jason's share = (2/5) x $40 = $16
Therefore, Jason made $16 from the lemonade stand profits.
2. For the expression not chosen, describe a situation that the expression might represent. x-8
The expression that represents the number of inches the plant grew is 8 - x.
What is Expression?An expression is combination of variables, numbers and operators.
A plant measured x inches tall last week and 8 inches tall this week.
We have to find the expression which represent the plant grew this week.
The number of inches the plant grew can be represented by the difference between its height this week and its height last week.
Eight minus x is the required expression.
8 - x
Hence, the expression that represents the number of inches the plant grew is 8 - x.
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Complete question
A plant measured x inches tall last week and 8 inches tall this week. Represent the number of inches the plant grew
A. X - 8
B. 8 - X
For the expression not chosen, describe a situation that the expression might represent.
A recent study showed that tea drinkers have lower stress levels than coffee drinkers. Tea drinkers are known to have a higher proportion of yoga practitioners than coffee drinkers, and they exercise on average two hours per week more than their coffee-drinking counterparts. What is the term used to describe these additional factors that might have an effect on the stress levels of tea drinkers?
The additional factors that might have an effect on the stress levels of tea drinkers are called confounding variables. Confounding variables are variables that are not the main focus of the study but may have an impact on the results.
The term used to describe these additional factors that might have an effect on the stress levels of tea drinkers is "confounding variables." Confounding variables are extraneous factors that can affect the relationship between two variables of interest and can lead to incorrect conclusions about the relationship. In this case, the higher proportion of yoga practitioners and the increased exercise among tea drinkers could be considered confounding variables because they may be influencing the observed relationship between tea drinking and lower stress levels, rather than tea consumption alone.
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square root of 64 minus 10 plus 13
Answer:
11
Step-by-step explanation:
[tex]\sqrt{64}[/tex] -10 + 13
8 - 10 + 13
-2 + 13
11
A student scores in a history class are listed 45 52 65 68 68 70 77 78 78 81 85 96 100 which of the following histogram correctly represent the data
Answer:
second
Step-by-step explanation:
Watson, Raimey
8 x 40
A gallon can of stain covers approximately 70 square feet of wooden deck. Joaquin has purchased 8 gallons of stain.
Select all deck sizes that Joaquin could fully cover if he must apply 2 coats to the deck.
10 x 18
13 x 22
14 x 20
17 x 17
Answer: A gallon of stain covers 70 square feet, so 8 gallons would cover 8 x 70 = 560 square feet. If Joaquin must apply 2 coats to the deck, he needs enough stain to cover the deck twice, so he needs 560 square feet x 2 = 1120 square feet.
Of the deck sizes listed, the largest one that Joaquin can fully cover with 2 coats of stain is 14 x 20 = 280 square feet, which is less than 1120 square feet. This means that Joaquin can fully cover all of the listed deck sizes if he must apply 2 coats of stain.
Step-by-step explanation:
f ( x ) = { 2 x + 4 , x ≤ − 2 4 + 1 2 x , − 2 < x < 2 − x + 5 , 2 ≤ x Which of the following is the graph of the function shown above? A line starts at a closed circle (minus 2, 0) and passes through (minus 4, minus 4). The second line starts at a closed circle (2, minus 3) and passes through (5, 0). The third line with 2 open circles at (2, 6) and (minus 2, 3) W. A line starts at a closed circle (minus 2, 0) and passes through (minus 4, minus 4). The second line starts at a closed circle (2, minus 3) and passes through (5, 0). The third line with 2 open circles at (2, 3) and (minus 2, 5) X. A line starts at a closed circle (minus 2, 0) and passes through (minus 4, minus 4). The second line starts at a closed circle (2, 3) and passes through (5, 0). The third line with 2 open circles at (minus 2, 3) and (2, 5) Y. A line starts at a closed circle (minus 2, 0) and passes through (minus 4, minus 4). The second line starts at an open circle (2, 3) and passes through (5, 0). The third line with an open circle at (minus 2, 3) and a closed circle at (2, 5) Z. A. W B. X C. Y D. Z
Answer:
The correct graph of the given function is option C. Y.
Step-by-step explanation:
The correct graph is option B (X) because it satisfies all the conditions specified in the function definition.
The first segment of the graph starts at x=-2 and goes to the left, passing through the point (-4,-4) and representing the equation 2x+4. The second segment of the graph starts at x=-2 and goes to the right, passing through the point (2,3) and representing the equation 4+1/2x. The third segment of the graph starts at x=2 and goes to the right, passing through the point (5,0) and representing the equation -x+5.
Option A (W) has a line that passes through the point (2,6), which is not on the graph of the function, and option C (Y) has a line that passes through the point (2,5), which is also not on the graph of the function. Option D (Z) has an open circle at (-2,3), which should be a closed circle according to the function definition, and a closed circle at (2,5), which should be an open circle according to the function definition.
Let X and Y be continuous random variables with joint density f
X
,
Y
(
x
,
y
)
=
e
−
y
,
f
o
r
0
<
x
≤
y
<
[infinity]
and 0 otherwise.
Find rho
X
Y
.
The correlation coefficient of X and Y is 1, since their joint density is always positive for x ≤ y.
The correlation coefficient of two continuous random variables X and Y is a measure of how similar the two variables are in terms of their behavior. In this case, X and Y have a joint density of e−y, for 0 < x ≤ y < ∞ and 0 otherwise. This implies that the correlation coefficient of X and Y is 1, since their joint density is always positive for x ≤ y. This means that there is a perfect linear relationship between the two variables, meaning that as one variable increases, the other will also increase by the same amount.
To calculate the correlation coefficient, we need to calculate the covariance and variances of X and Y. The covariance is calculated by integrating the joint density of X and Y over the given range. The variance of X and Y is then calculated by taking the square root of the expected value of the squares of the differences between the expected value of X and Y and their respective observed values. Since the joint density of X and Y is always positive for x ≤ y, the correlation coefficient of X and Y will always be 1.
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If sin(θ)>0 and sec(θ)<0, in which quadrant does θ lie?
Answer:
Quadrant II
Step-by-step explanation:
sin (∅) > 0 means sin (∅)is positive
sec (∅) < 0 means sec (∅) is negative
thus,
∅ lies in quadrant II
NO LINKS!! URGENT HELP PLEASE!!
Find the shaded area of each figure, round your answer to one decimal place if necessary.
Answer:
7) 216 ft²
8) 106 yd²
9) 200 m²
Step-by-step explanation:
To calculate the area of each given figure, subtract the area of the cut-out rectangle (marked in blue on the attached diagram) from the area of the larger rectangle.
[tex]\boxed{\begin{minipage}{5cm}\underline{Area of a rectangle}\\\\$A=w\cdot l$\\\\where:\\ \phantom{ww} $\bullet$ \quad $w$ is the width.\\ \phantom{ww} $\bullet$ \quad $l$ is the length.\\\end{minipage}}[/tex]
Question 7Note: The height of the larger rectangle is not complete. I have assumed it is 12 ft.
[tex]\begin{aligned}\textsf{Total Area}&=\textsf{Larger rectangle}-\textsf{Cut-out rectangle}\\&=21 \cdot 12- 6\cdot 6\\&=252-36\\&=216\; \sf ft^2\end{aligned}[/tex]
Question 8[tex]\begin{aligned}\textsf{Total Area}&=\textsf{Larger rectangle}-\textsf{Cut-out rectangle}\\&= 17\cdot 10- (17-9)\cdot 8\\&= 17\cdot 10- 8\cdot 8\\&=170-64\\&=106\; \sf yd^2\end{aligned}[/tex]
Question 9[tex]\begin{aligned}\textsf{Total Area}&=\textsf{Larger rectangle}-\textsf{Cut-out rectangle}\\&= 15\cdot 20- 10\cdot 10 \\&=300-100\\&=200\; \sf m^2\end{aligned}[/tex]
27
Select the correct answer.
Number of Players on the Team Time Taken to Complete Game (in minutes)
Teams with varying numbers of players are playing a group card game. The time taken by each team to complete one game is given in the table.
What is the relationship between the two variables?
2
3
4
5
O A. positive linear association
O B. exponential relationship
O C.
negative linear association
32
26
20
14
The relationship between the two variables negative linear association.
What is Linear Association?A straight-line link between two variables is referred to statistically as a linear relationship (or linear association).
Linear relationships can be represented graphically or mathematically as the equation y = mx + b.
Given:
The data table is organized as follows:
1 2 3 4 5
32 26 20 14 8
We see that more the number of members in the team increase, the more the times decrease.
The correlation is a negative linear association, we conclude.
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Sergio has
p
pp paintings in his art collection. He and other local painting collectors agreed to donate a total of
48
4848 paintings to the local museum. Each of the
12
1212 collectors will donate the same number of paintings.
How many paintings will Sergio have in his art collection after his donation?
Write your answer as an expression.
Answer: Let's assume that each of the 12 collectors donates n paintings. Then the total number of paintings donated will be 12 * n. We know that the total number of paintings donated by all collectors is 48, so we have the equation:
12 * n = 48
Dividing both sides by 12, we find that each collector donates n = 4 paintings. So, if Sergio has p paintings in his collection, after his donation he will have p - 4 paintings in his collection. The final answer is:
p - 4
Step-by-step explanation:
b) How much
2. The original price of a MacBook is $1400. Students get a 10% discount. How much will
after the discount?
Show work
nswer:
Answer:
$1400 divided by 10 = $140
$1400 - $140 = $1260
Over 1000 people try to climb mt Everest every year. Of those who try to climb Everest, 31 precent succeed. The probability that a climber is at least 60 years old is 0.04 The probability that a climber is at least 60 years old and succeeds in climbing Everest is 0.005.
P(success I at least 60 years old) = 0.125.
What is the probability?The possibility of an event in time is known as a probability in mathematics. How frequently does the incidence occur over the course of a specific time period, in plain English?
Given:
Over 1000 people try to climb mt Everest every year.
Of those who try to climb Everest, 31 percent succeed.
The probability that a climber is at least 60 years old is 0.04.
The probability that a climber is at least 60 years old and succeeds in climbing Everest is 0.005.
P(success I at least 60 years old) = 0.005/0.04 = 0.125
Therefore, the probability is 0.125.
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fill in the blank. the ___performs all arithmetic operations (for example, addition and subtraction) and all logic operations (such as sorting and comparing numbers). (please use acronym) multiple choice question.
The CPU (Central Processing Unit) performs all arithmetic operations (for example, addition and subtraction) and all logic operations (such as sorting and comparing numbers).
The acronym that fills in the blank is CPU, which stands for Central Processing Unit. The CPU is essentially the brain of a computer, responsible for processing all the information that flows through the system.
Arithmetic operations are those that involve mathematical calculations, such as addition, subtraction, multiplication, and division. These are relatively straightforward tasks for the CPU, which can perform them quickly and accurately.
Logic operations, on the other hand, involve comparing and manipulating data based on various conditions.
CPU has the ability to perform logic operations is a crucial aspect of computing, as it allows computers to make decisions and process information based on a set of rules or conditions.
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The equation below describes a parabola. If a is negative, which way does the parabola open?
y= ax?
If a is negative, the parabola opens down. Option C is the correct option.
What is a parabola?
Any point on a parabola is at an equal distance from both the focus, a fixed point, and the directrix, a fixed straight line. A parabola is a U-shaped plane curve. The topic of conic sections includes parabola, and all of its concepts are covered here.
A polynomial function of the second degree is a quadratic function. A quadratic function has this general form:
y = ax² + bx + c
A parabola is a name for a quadratic function's graph.
A parabola resembles the letter "U" or an upside-down "U" in general shape.
If the leading coefficient is greater than zero, the parabola opens upward; if the leading coefficient is less than zero, the parabola opens downward. This simple rule can be used to determine whether the graph of a quadratic function opens upward or downward.
Given equation is
y = ax²
The leading coefficient is a and it is a negative number. Thus the parabola opens down.
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PLEASE please please help, it will mean the world to me, and if you are right I will give brainliest. And try to show work! Mr Smith is putting a brick border around his irregular shaped garden. Before installing the border, he must cut the bricks to fit the angles of the garden. Use the given measures to answer this question. What are the angle measures of each vertex of the yard? Show your work.
The value of x is 24. The angle measures of each vertex of the yard are m∠A = 160°, m∠B = 142°, m∠C = 120°, m∠D = 156°, m∠E = 31°, m∠F = 111°.
What is a polygon?
A polygon is a closed polygonal chain made up of a finite number of straight line segments and is a type of plane figure in geometry. A polygon is a region that is bounded by a bounding circuit, a bounding plane, or both. A polygonal circuit's segments are referred to as its edges or sides.
The formula of the sum of interior angles of a polygon is (n - 2)×180°, where n is number of sides.
The number of sides of the given irregularly shaped garden is 6.
The sum of the interior angles of the garden is (6 - 2)×180° = 720°
Also given:
m∠A = (7x - 8)°, m∠B = (4x + 46)°, m∠C = (5x)° , m∠D = (6x + 12)°, m∠E = (x + 7)°, m∠F = (5x - 9)°.
The sum of the interior angles of the garden is
(7x - 8)° + (4x + 46)° + (5x)° + (6x + 12)° + (x + 7)° + (5x - 9)°
Therefore,
(7x - 8)° + (4x + 46)° + (5x)° + (6x + 12)° + (x + 7)° + (5x - 9)° = 720°
Combine like terms:
(7x +4x + 5x + 6x + x + 5x) + (-8 +46 + 12 + 7 - 9) = 720
28x + 48 = 720
Subtract 48 from both sides:
28x = 672
Divide both sides by 28:
x = 24
Putting x = 28 in the given angles:
m∠A = (7×24 - 8)° = 160°
m∠B = (4×24 + 46)°= 142°
m∠C = (5×24)° = 120°
m∠D = (6×24 + 12)°= 156°
m∠E = (24 + 7)° = 31°
m∠F = (5×24 - 9)° = 111°
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the geometric distribution arises as the distribution of the number of times we flip a coin until it comes up heads. consider now the distribution of the number of flips until the -th head appears, where each coin flip comes up heads independently with probability . this is known as the negative binomial distribution, and we also write . find . hint: here counts the number of flips including the flip with the -th head. mark the correct expression for , below.
The correct expression for P(X = k) will be [tex]P(X = k) = \binom{k-1}{r-1} \left(\frac{1}{2}\right)^k[/tex]
Given,
The geometric distribution arises as the distribution of the number of times we flip a coin until it comes up heads. consider now the distribution of the number of flips until the -th head appears, where each coin flip comes up heads independently with probability.
The negative binomial distribution describes the probability of getting the -th success (in this case, heads) on the th trial, given a probability p of success on each trial.
We can write this as:
[tex]P(X = k) = \binom{k-1}{r-1} p^r (1-p)^{k-r}[/tex]
where k is the number of flips needed to get r successes, including the rth success.
In this case, we want the distribution of the number of flips until the rth head appears,
so we can set p = 1/2,
since the coin is fair.
We also need to adjust the formula to count the number of flips, including the flip with the rth head.
Since we need r heads to appear, the last head must appear on the rth flip, so we can write:
[tex]P(X = k) = \binom{k-1}{r-1} \left(\frac{1}{2}\right)^r \left(\frac{1}{2}\right)^{k-r+1}[/tex]
Simplifying the expression,
we get:
[tex]P(X = k) = \binom{k-1}{r-1} \left(\frac{1}{2}\right)^k[/tex]
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a sample of 40 country cd recordings of willie nelson has been examined. the average playing time of these recordings is 51.3 minutes, and the standard deviation is s
We can be 95% confident that the true mean playing time of all Willie Nelson recordings is between 48.89 and 53.71 minutes.
Using a t-multiplier for a 95% confidence interval with 39 degrees of freedom (n-1), we get t* = 2.022.
The margin of error is t* times the standard error of the mean, which is s / sqrt(n), where n is the sample size.
Thus, the margin of error is 2.022 * (5.8 / sqrt(40)) = 2.41 minutes.
To construct the confidence interval, we add and subtract the margin of error to the sample mean:
Lower limit = 51.3 - 2.41 = 48.89
Upper limit = 51.3 + 2.41 = 53.71
Therefore, we can be 95% confident that the true mean playing time of all Willie Nelson recordings is between 48.89 and 53.71 minutes.
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determine the volume of the solid with a circular base of radius a whose cross sections are squares that are perpendicular to the base.
The volume of the solid is [tex]4a^2h[/tex].
Each square cross-section has a side length equal to the diameter of the circle, which is 2a.
Therefore, the area of each cross-section is
[tex](2a)^2 = 4a^2[/tex]
The volume of the solid can be found by integrating the area of the cross sections over the height of the solid.
Since the cross-sections are perpendicular to the base, the height of each cross-section is equal to the thickness of the solid, which we can denote as dx.
Thus, the volume of the solid is given by the integral of the cross-sectional area with respect to x, from x = 0 to x = h, the height of the solid:
V = ∫ (0 to h) [tex]4a^2 dx[/tex]
V = [tex]4a^2[/tex] ∫(0 to h) dx
V = [tex]4a^2[/tex] (0 to h)
V = [tex]4a^2[/tex] (h - 0)
V = [tex]4a^2h[/tex]
Therefore, the volume of the solid is [tex]4a^2h[/tex]
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5. Identify the mean and standard deviation of the graph.
O
8.2 13.4 18.6 23.8 29 34.2 39.4
mean = 18.6; standard deviation = 5.2
mean = 23.8; standard deviation 2.7
mean = 23.8; standard deviation = 5.2
mean = 18.6; standard deviation = 2.7
The mean and the standard deviation for the data-set are given as follows:
mean = 23.8; standard deviation = 5.2.
How to obtain the mean and the standard deviation?The mean of a data-set is given by the sum of all the observations in the data-set divided by the number of observations, hence:
Mean = (8.2 + 13.4 + 18.6 + 23.8 + 29 + 34.92 + 39.4)/7
Mean = 23.8.
The standard deviation is given by the square root of the sum of the differences squared between each observation and the mean, divided by the number of observations, hence:
s = sqrt([(8.2-23.8)² + (13.4-23.8)² + (18.6-23.8)² + (23.8-23.8)² + (29-23.8)² + (34.92-23.8)² + (39.4-23.8)²]/7)
s = 5.2.
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Do you think global warming will have an impact on you during your lifetime? A CBS News/New York Times poll of 1000 adults in the United States asked this ques- tion (CBS News website, December, 2014). Consider the responses by age groups shown below Response Age 18-29 30+Yes 134 131No 293 432Unsure a. What is the probability that a respondent 18-29 years of age thinks that global warming will not pose a serious threat during his/her lifetime?b. What is the probability that a respondent 30+ years of age thinks that global warming will not pose a serious threat during his/her lifetime? c. For a randomly selected respondent, what is the probability that a respondent answers yes? d. Based on the survey results, does there appear to be a difference between ages 18-29 and 30+ regarding concern over global warming?
From the given data the probability that a respondent 18-29 years and 30+ years are 0.536 and 0.654 espectively. The probability that they answer yes (i.e. global warming will have an impact on them during their lifetime) is 0.265. There also appears to be a difference between ages 18-29 and 30+ regarding concern over global warming.
The probability that a respondent 18-29 years of age thinks that global warming will not pose a serious threat during his/her lifetime is:
P(18-29 and No) = 293/(134 + 293 + 117) = 0.536
The probability that a respondent 30+ years of age thinks that global warming will not pose a serious threat during his/her lifetime is:
P(30+ and No) = 432/(131 + 432 + 178) = 0.654
For a randomly selected respondent, the probability that they answer yes (i.e. global warming will have an impact on them during their lifetime) is:
P(Yes) = (134 + 131)/(134 + 131 + 293 + 432 + 117 + 178) = 0.265
Yes, there appears to be a difference between ages 18-29 and 30+ regarding concern over global warming. The probability of a respondent 30+ years of age thinking that global warming will not pose a serious threat during their lifetime (0.654) is higher than the corresponding probability for respondents 18-29 years of age (0.536). This suggests that older respondents are less concerned about global warming than younger respondents. However, a formal statistical test would be needed to confirm this difference.
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