Answer:
The time it will take is 13 hours
Step-by-step explanation:
From the given statement, we can generate the following inverse proportion relationship between t and s
t ∝ 1/s
[tex]t = \frac{k}{s} \\\\where;\\\\k \ is \ constant\\\\k = t_1s_1 = t_2s_2 \\\\t_2 = \frac{t_1s_1}{s_2} \\\\t_2 = \frac{12 \times 52}{48} \\\\t_2 = 13 \ hours[/tex]
The time it will take is 13 hours
Dannette and Alphonso work for a computer repair company. They must include the time it takes to complete each repair in their repair log book. The dot plots show the number of hours each of their last 12 repairs took. Part a. Calculate the median, mean, IQR, and standard deviation of each data set. Part b. Which measure of central tendency and spread should you use to compare the two data sets? Explain your reasoning. Part c. Determine whether there are any outliers in either data set. Dannette's Repair Times х х X X X X Х Х + 9 + 1 0 Relations 2 3 4 8 10 12 5 6 7 Repair Time (hours) Geometry Alphonso's Repair Times Groups X Trigonometry X Х X X X х X х Statistics 7 X + 3 10 9 0 4 12 Series 8 1 2 5 7 Repair Time (hours) Greek
PLZ HELP
Answer:
(a):
Dannette Alphonso
[tex]\bar x_D = 4.33[/tex] [tex]\bar x_A = 5.17[/tex]
[tex]M_D = 2.5[/tex] [tex]M_A = 5[/tex]
[tex]\sigma_D = 3.350[/tex] [tex]\sigma_A = 1.951[/tex]
[tex]IQR_D = 7[/tex] [tex]IQR_A = 1.5[/tex]
(b):
Measure of center: Median
Measure of spread: Interquartile range
(c):
There are no outliers in Dannette's dataset
There are outliers in Alphonso's dataset
Step-by-step explanation:
Given
See attachment for the appropriate data presentation
Solving (a): Mean, Median, Standard deviation and IQR of each
From the attached plots, we have:
IQR_A = 1.5 ---- Dannette
[tex]A = \{3,4,4,4,4,5,5,5,5,6,6,11\}[/tex] ---- Alphonso
n = 12 --- number of dataset
Mean
The mean is calculated
[tex]\bar x = \frac{\sum x}{n}[/tex]
So, we have:
[tex]\bar x_D = \frac{1+1+1+1+2+2+3+7+8+8+9+9}{12}[/tex]
[tex]\bar x_D = \frac{52}{12}[/tex]
[tex]\bar x_D = 4.33[/tex] --- Dannette
[tex]\bar x_A = \frac{3+4+4+4+4+5+5+5+5+6+6+11}{12}[/tex]
[tex]\bar x_A = \frac{62}{12}[/tex]
[tex]\bar x_A = 5.17[/tex] --- Alphonso
Median
The median is calculated as:
[tex]M = \frac{n + 1}{2}th[/tex]
[tex]M = \frac{12 + 1}{2}th[/tex]
[tex]M = \frac{13}{2}th[/tex]
[tex]M = 6.5th[/tex]
This implies that the median is the mean of the 6th and the 7th item.
So, we have:
[tex]M_D = \frac{2+3}{2}[/tex]
[tex]M_D = \frac{5}{2}[/tex]
[tex]M_D = 2.5[/tex] ---- Dannette
[tex]M_A = \frac{5+5}{2}[/tex]
[tex]M_A = \frac{10}{2}[/tex]
[tex]M_A = 5[/tex] ---- Alphonso
Standard Deviation
This is calculated as:
[tex]\sigma = \sqrt{\frac{\sum(x - \bar x)^2}{n}}[/tex]
So, we have:
[tex]\sigma_D = \sqrt{\frac{(1 - 4.33)^2 +.............+(9- 4.33)^2}{12}}[/tex]
[tex]\sigma_D = \sqrt{\frac{134.6668}{12}}[/tex]
[tex]\sigma_D = 3.350[/tex] ---- Dannette
[tex]\sigma_A = \sqrt{\frac{(3-5.17)^2+............+(11-5.17)^2}{12}}[/tex]
[tex]\sigma_A = \sqrt{\frac{45.6668}{12}}[/tex]
[tex]\sigma_A = 1.951[/tex] --- Alphonso
The Interquartile Range (IQR)
This is calculated as:
[tex]IQR =Q_3 - Q_1[/tex]
Where
[tex]Q_3 \to[/tex] Upper Quartile and [tex]Q_1 \to[/tex] Lower Quartile
[tex]Q_3[/tex] is calculated as:
[tex]Q_3 = \frac{3}{4}*({n + 1})th[/tex]
[tex]Q_3 = \frac{3}{4}*(12 + 1})th[/tex]
[tex]Q_3 = \frac{3}{4}*13th[/tex]
[tex]Q_3 = 9.75th[/tex]
This means that [tex]Q_3[/tex] is the mean of the 9th and 7th item. So, we have:
[tex]Q_3 = \frac{1}{2} * (8+8) = \frac{1}{2} * 16[/tex] [tex]Q_3 = \frac{1}{2} * (5+6) = \frac{1}{2} * 11[/tex]
[tex]Q_3 = 8[/tex] ---- Dannette [tex]Q_3 = 5.5[/tex] --- Alphonso
[tex]Q_1[/tex] is calculated as:
[tex]Q_1 = \frac{1}{4}*({n + 1})th[/tex]
[tex]Q_1 = \frac{1}{4}*({12 + 1})th[/tex]
[tex]Q_1 = \frac{1}{4}*13th[/tex]
[tex]Q_1 = 3.25th[/tex]
This means that [tex]Q_1[/tex] is the mean of the 3rd and 4th item. So, we have:
[tex]Q_1 = \frac{1}{2}(1+1) = \frac{1}{2} * 2[/tex] [tex]Q_1 = \frac{1}{2}(4+4) = \frac{1}{2} * 8[/tex]
[tex]Q_1 = 1[/tex] --- Dannette [tex]Q_1 = 4[/tex] ---- Alphonso
So, the IQR is:
[tex]IQR = Q_3 - Q_1[/tex]
[tex]IQR_D = 8 - 1[/tex] [tex]IQR_A = 5.5 - 4[/tex]
[tex]IQR_D = 7[/tex] --- Dannette [tex]IQR_A = 1.5[/tex] --- Alphonso
Solving (b): The measures to compare
Measure of center
By observation, we can see that there are outliers is the plot of Alphonso (because 11 is far from the other dataset) while there are no outliers in Dannette plot (as all data are close).
Since, the above is the case; we simply compare the median of both because it is not affected by outliers
Measure of spread
Compare the interquartile range of both, as it is arguably the best measure of spread, because it is also not affected by outliers.
Solving (c): Check for outlier
To check for outlier, we make use of the following formulas:
[tex]Lower =Q_1 - 1.5 * IQR[/tex]
[tex]Upper =Q_3 + 1.5 * IQR[/tex]
For Dannette:
[tex]Lower = 1 - 1.5 * 7 = -9.5[/tex]
[tex]Upper = 8 + 1.5 * 7 = 18.5[/tex]
Since, the dataset are all positive, we change the lower outlier to 0.
So, the valid data range are:
[tex]Valid = 0 \to 18.5[/tex]
From the question, the range of Dannette's dataset is: 1 to 9. Hence, there are no outliers in Dannette's dataset
For Alphonso:
[tex]Lower = 4 - 1.5 * 1.5 =1.75[/tex]
[tex]Upper = 5.5 + 1.5 * 1.5 =7.75[/tex]
So, the valid data range are:
[tex]Valid = 1.75\to 7.75[/tex]
From the question, the range of Alphonso's dataset is: 3 to 11. Hence, there are outliers in Alphonso's dataset
If the exponential model f(x)=3(2)x is written with the base e, it will take the form A0ekx. What is A0 and what is k?
Answer:
Answer in pic
Step-by-step explanation:
The required value of A₀ = 3 and k = ln 2, as of the given exponential model.
What is an exponential function?The function which is in format f(x) =a^x where a is constant and x is variable, the domain of this exponential function lies (-∞, ∞).
here,
Since.
[tex]a^x = e^{xlna}[/tex]
According to the question,
[tex]3(2)^x = A_oe^{kx}\\3e^{xln2} = A_oe^{kx}[/tex]
Now
Compare the values,
A₀ = 3 and k = ln 2,
Thus, According to the stated exponential model, A0 = 3 and k = ln 2.
Learn more about exponential function here:
brainly.com/question/15352175
#SPJ2
What does it mean to the rise over run when the slope is an integer? a. the rise number is one c. the run part of the slope is going to be one b. the run number is always negative d. there will be no slope Please select the best answer from the choices provided A B C D
Answer: integer is a whole number
Eg
10/2 = 5/1 = 5 = integer
But 12/8 = 3/2 = 1.5 = not an integer
So really, slope = integer
Means rise greater than run
And run is a factor of rise
Or run = 1 will satisfy the above too :)
Answer:
C. The run part of the slope is going to be one
Step-by-step explanation:
.
What is the radius for the circle given by the equation x^2+(y-1)^2=12?
Round your answer to the nearest thousandth.
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Answer:
3.464
Step-by-step explanation:
Comparing the given equation to the standard form equation of a circle:
(x -h)^2 +(y -k)^2 = r^2
we find the center to be (h, k) = (0, 1) and the radius to be √12 = 2√3.
The problem statement tells us to round the radius to the nearest thousandth, so it will be ...
2√3 ≈ 3.4641016 ≈ 3.464 . . . radius of the circle
In the following distribution, P(X<2) = 0.35, and expected value is 1.9
X 0 1 2 3 4
P(X) 0.10 A 0.35 B C
Required:
a. Use the fact that P(X< 2) = 0.35 to find the value of A.
b. Determine the value of B.
c. Determine the value of C.
Solution :
We have :
X 0 1 2 3 4
P(X) 0.10 A 0.35 B C
a). P(X < 2) = 0.35
P(X < 2) = P(X = 0) + P(X = 1) = 0.35
⇒ 0.10 + A = 0.35
⇒ A = 0.25
So the value of A is 0.25
b). The total probability = 1
So ,
0.10 + A + 0.35 + B + C = 1
0.10 + 0.25 + 0.35 + B + C = 1
B + C = 1 - 0.70
B + C = 0.30 ......(i)
We have the expected value = 1.9
So, [tex]$\sum X P(X) = 19$[/tex] for x = 0, 1, 2, 3, 4
⇒ (0 x 0.10) + (1 x 0.25) + (2 x 0.35) + (3 x B) + (4 x C) = 1.9
⇒ 0 + 0.25 + 0.70 + 3B + 4C = 1.9
⇒ 3B + 4C = 1.9 - 0.95
⇒ 3B + 4C = 0.95 ...................(ii)
From (i), we take the value of B = 0.30 - C and substitute it in the equation (i), we get,
⇒ 3( 0.30 - C) + 4C = 0.95
⇒ 0.90 - 3C + 4C = 0.95
⇒ C = 0.95 - 0.90
= 0.05
Now substituting the value of C = 0.05 in (ii), we get,
⇒ B = 0.05 = 0.30
⇒ B = 0.25
c). The value of C is 0.05
17. A loan of $8000 was paid back in 2
years in monthly payments of $400.
The interest on the loan as a
percentage, was
A. 5%
B. 8-%
C. 162 %
16
D. 20%
Answer:
D. 20%
Step-by-step explanation:
2 years = 24 months
400 × 24 = 9600
9600 - 8000 = 1600
1600/8000 = 1/5
1/5 = 20%
Find the value for the side marked below.
Round your answer to the nearest tenth.
13
23°
у
у
[?]
Enter
Answer:
y = 30.96
Step-by-step explanation:
take 23 degree as reference angle
using tan rule
tan 23 = opposite / adjacent
0.42 = 13/y
y = 13/0.42
y = 30.96
FIND THE ∛ OF 188
(USE √
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Answer:
∛188 ≈ 5.72865
Step-by-step explanation:
Any scientific or graphing calculator or spreadsheet can tell you the cube root of 188.
∛188 ≈ 5.72865431598...
__
You know that 5³ = 125 and 6³ = 216, so the root will lie between 5 and 6, closer to 6. As a first approximation, you can figure it is about ...
x = ∛188 ≈ 5 + (188-5³)/(6³ -5³) = 5 + 63/89 ≈ 5.71
You can figure this much using a 4-function calculator.
A closer approximation (x') can be had using the iteration formula ...
x' = (2x³ +188)/(3x²)
For x = 5.71, the value of x' is ...
x' ≈ (2×5.71³ +188)/(3×5.71²) ≈ 560.3388/97.8123 ≈ 5.7287
This value is correct when the root is rounded to 4 decimal places. Another execution of the iteration formula using this value will give the root accurate to 9 decimal places.
find the area of the following figures:
Answer:
Area = 156 square cm
Step-by-step explanation:
A school principal wants to know more about the number of students absent each day. He counts the number of students absent each day for one week: {24, 18, 31,
Answer:
6.27
Step-by-step explanation:
We are to obtain the standard deviation of the given values :
{24, 18, 31,25, 34}
The standard deviation = √(Σ(x - mean)²/ n)
The mean = (ΣX) /n
Using calculator to save computation time :
The standard deviation, s = 6.27 (2 decimal places)
Solve this for me guys
Answer:
x = 7.348
Step-by-step explanation:
I don't really know how to explain this over a computer, but it is correct. Answer credit of Omnicalculator.
Hope that this helps!
Find the equation (in terms of x ) of the line through the points (-2,5) and (3,4)
y=
Hi there!
»»————- ★ ————-««
I believe your answer is:
[tex]y=-\frac{1}{5}x+\frac{23}{5}[/tex]
»»————- ★ ————-««
Here’s why:
We first need to find the slope of the equation.⸻⸻⸻⸻
[tex]\boxed{\text{\underline{Slope Is...}}}\\\\\rightarrow\frac{y_2-y_1}{x_2-x_1}\\\\\boxed{\text{Key:}}\\\\\rightarrow (x_1,y_1)\text{ and }(x_2,y_2) - \text{Two Points Given}[/tex]
⸻⸻⸻⸻
[tex]\boxed{\text{Calculating the Slope...}}\\\\\rightarrow m=\frac{4-5}{3-(-2)}\\\\\rightarrow m=\frac{-1}{5}\\\\\rightarrow \boxed{m=-\frac{1}{5}}\\\\\\\text{The slope is } -\frac{1}{5}.[/tex]
⸻⸻⸻⸻
We then need to find the y-intercept of the equation.⸻⸻⸻⸻
[tex]\boxed{\text{Calculating the intercept...}}\\\\y=-\frac{1}{5}x+b\\-------------\\\rightarrow 4 = -\frac{1}{5}(3) +b\\\\\rightarrow4= -\frac{3}{5}+b\\\\\rightarrow4+\frac{3}{5}= -\frac{3}{5}+\frac{3}{5} +b\\\\\rightarrow \boxed{\frac{23}{5}=b}[/tex]
⸻⸻⸻⸻
[tex]\text{The equation should be: }\boxed{ y=-\frac{1}{5}x+\frac{23}{5} }.[/tex]
»»————- ★ ————-««
Hope this helps you. I apologize if it’s incorrect.
3. Betty rode her bike down a block that was 50 meters long. How many millimeters did she ride?
Answer:
50,000 millimeters
Step-by-step explanation:
Hope this helps : ) I have no explanation but it's correct
The solution set for -18 < 5x - 3 is _____.
3 > x
3 < x
-3 < x
-3 > x
Answer:
[tex]-3 < x[/tex]
Step-by-step explanation:
Given
[tex]-18 < 5x-3[/tex]
Required
The solution
[tex]-18 < 5x-3[/tex]
Add 3 to both sides
[tex]3-18 < 5x-3+3[/tex]
[tex]-15 < 5x[/tex]
Divide both sides by 5
[tex]-3 < x[/tex]
There are some Rs2 and Rs5 coins in a box. The ratio of the number of Rs2 coins to the number of Rs5 coins is 1:3. The value of all the Rs5 coins is Rs45. What is the value of all the Rs2 coins in the box?
Given:
The ratio of the number of Rs2 coins to the number of Rs5 coins is 1:3.
The value of all the Rs5 coins is Rs45.
To find:
The value of all the Rs2 coins in the box.
Solution:
Let x be the number of Rs2 coins and y be the number of Rs5 coins.
The value of all the Rs5 coins is Rs45.
[tex]5y=45[/tex]
[tex]y=\dfrac{45}{5}[/tex]
[tex]y=9[/tex]
The ratio of the number of Rs2 coins to the number of Rs5 coins is 1:3.
[tex]\dfrac{x}{y}=\dfrac{1}{3}[/tex]
[tex]\dfrac{x}{9}=\dfrac{1}{3}[/tex]
Multiply both sides by 9.
[tex]\dfrac{x}{9}\times 9=\dfrac{1}{3}\times 9[/tex]
[tex]x=3[/tex]
The value of all the Rs2 coins in the box is:
[tex]\text{Required value}=2x[/tex]
[tex]\text{Required value}=2(3)[/tex]
[tex]\text{Required value}=6[/tex]
Therefore, the value of all the Rs. 2 coins in the box is Rs. 6.
A bicycle shop owner offers five styles of mountain bikes for $450, $275, $675, $490, and $300. He wants to increase the mean price but keep the median price and range of prices the same. Suggest a new set of prices for the five styles
Answer:
275, 350, 450, 550, 675
Step-by-step explanation:
Arrange in order
275, 300, 450, 490, 675
range 275 to 675
median 450
mean 438
---------------------------
Raise 300 to 350
Raise 490 to 550
New set of prices
275, 350, 450, 550, 675
range 275 to 675 same
median 450 same
mean 460 increased
Answer:
One set of prices could be: {275,300,450,600,675}
Another set could be: {275,300,450,600,675}
There are many other solutions possible.
====================================================
Explanation:
A = {450, 275, 675, 490, 300}
B = {275, 300, 450, 490, 675}
Set A is the original set of values in the order they were given to you. Set B is the sorted version of set A from smallest to largest.
The mean is found by adding up the values and dividing by 5 (because there are five items in the set).
The mean is (275+300+450+490+675)/5 = 2190/5 = 438. The shopkeeper wants to increase the mean to something larger, but keep the median and range the same.
The median is the middle most number. In set B, we can see that is 450. So the median is 450. We want to keep the median the same at 450.
The range is the difference in min and max
range = max - min = 675-275 = 400
We want to keep the range at 400
---------------------------
There are a number of ways to increase the mean, while keeping the median and range the same.
Let's say we keep the min and max the same. In order to increase the mean, we need to increase the 490 (second largest value) to something larger. Let's bump that up to 600 for instance.
Recomputing the mean gets us
(275+300+450+600+675)/5 = 2300/5 = 460
The old mean was 438 and the new mean is now 460. The mean has increased. This is due to the larger price pulling on the mean to get the mean to increase.
The median is still 450 because it's still in the direct middle of set C
C = {275,300,450,600,675}
The range is still the same as well because we haven't changed the min and max.
---------------------------
So one possible set could be
C = {275,300,450,600,675}
We could also have
D = {275,400,450,500,675}
The difference is that the 300 bumped to 400, and the 600 dropped to 500. You should find that the median and range are the same, while the mean is 460.
There are many possible solutions here.
holaaaaaaaaaaaa plz help me i need it quick △SEA is rotated 270 degrees about the origin. Draw the image of this rotation.
Answer:
A will have this new coordinate (2, 1).
S will have this new coordinate (-2, 7).
E will have this new coordinate (2, 7).
Step-by-step explanation:
A is the coordinate (-1, 2).
S is the coordinate (-7, -2).
E is the coordinate (-7, 2).
To rotate that figure 270 grades (is the same to rotate 90 grades) we need to convert those coordinates to this (y, -x).
So,
A will have this new coordinate (2, 1).
S will have this new coordinate (-2, 7).
E will have this new coordinate (2, 7).
Last month Rudy’s Tacos sold 22 dinner specials. The next month they released a new commercial and sold 250% of last month’s dinners. How many dinner specials did they sell this month?
Answer:
the answer is 2
Step-by-step explanation: because 250 -22 is i dont even know
Answer:
55
Step-by-step explanation:
Solve the inequality c+12<16
Answer:
c+12<16
c=16-12
c=4
answer is this
Angle x is conterminal with angle y. If the measure of angle x is greater than the measure of angle y, which statement is true regarding the values of x and y?
x = y - 180n, for any positive integer n
x = y - 360n, for any integer n
x = y + 360n, for any positive integer n
x = y + 180n, for any integer n
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Answer:
x = y + 360n, for any positive integer n
Step-by-step explanation:
Since x is greater than y, something must be added to y to get x. Angles have the same co-terminal ray at multiples of 360°. Then the amount added to y must be some multiple of 360°:
x = y + 360n . . . . . for positive integer n
Question 10 (1 point) Find the volume of the figure. 2.5 ft 3 ft 2 ft 6 ft. What is the volume of the figure?
Answer:
I don’t know what type of figure you are talking about. But if there is supposed to be a picture attached, we see nothing
Step-by-step explanation:
You could repost this question though, I’ll be glad to help on that other question!
Juan y rosa van a repartirse un pastel por partes iguales sin que sobre nada .Si de la fiesta sobró 3/4pastel .¿cuanto le tocó a cada uno?
Usando el método de polya:
a. Que se pregunta?
la fracción de cuánto obtendría cada uno de ellos y compartiría por igual.b. ¿Cuáles son los datos dados?
¾ tarta, 2 personas (Juan y Rosa)c. ¿Cuál es la operación que se utilizará?
divisiónd. oración numérica:
¾ ÷ 2e. Solución y respuesta completa:
[tex] \frac{3}{4} \div 2 \\ = \frac{3}{4} \times \frac{1}{2} \\ = \frac{3}{8} [/tex]
explicación paso a paso:
Multiplica por el recíproco: Dividir es equivalente a multiplicar por el recíproco.Multiplicar: multiplica las fraccionesForma decimal: 0.375
☆彡Hanna#CarryOnLearning
what of the following functions is graphed below
being timed help quickly will mark brainliest !!!
55
3. Patrick paid $20 for 5 peaches. How much did he pay per peach? Show
your work!
Answer:
Step-by-step explanation:
LA EDUCACION ES IMPIRTANTE YA QUE PROMUEVE UN MEJOR DESARROLLO DE LOS NIÑOS,NIÑAS Y ADOLESCENTES QUE LOS HACE FOMENTAR UN VINCULO MUY ESPECIAL CON SUS MAESTROS,COMPAÑEROS QUE LOS HACE SENTIR QUE SON PARTE DE SU FAMILIA ADEMAS ELLOS PASAN LA MAYORIA DE TIEMPO EN LA ESCUELA QUE LOS HACE SENTIRSE MÁS CÓMODOS COMO SI FUERA SU PROPIO HOGAR
Answer:
4 peaches
Step-by-step explanation:
$20/5 = 4 peaches
HELP PLEASE MATH PROBLEM
Answer:
x=41
Step-by-step explanation:
LM =JM
154=4x-10
154+10=4x
164=4x
164/4=4x/4
41=x
hope this is helpful
Geometric Probability
Find the probability that a point chosen randomly inside the larger rectangle is in each given smaller shape. Round to the nearest percent. PLEASE HELP!
1) The circle
2) The smaller rectangle
3) Not the circle or smaller rectangle
Answer:
Step-by-step explanation:
1) P= Area of Circle/ Area of large rectangle
Area of the circle = pi·r² = pi·2²=4 pi ft.²
Area of large rectangle= l·w -12·10 =120 ft.²
P = 4pi/120 rewrite 120 as 4·30
P= 4 pi/4*30 = pi/30 = 3.14/40 ≈ .1047 ≈10% (because .1047·100 =10.47≅10)
2) P = Area of smaller rectangle/ Area of large rectangle
Area of smaller rectangle = l·w = 2·4 =8 ft.²
Area of large rectangle=l·w = 12·10=120 ft²
P= 8/120 ≅ .0666≅ 7% (because .0666·100 =6.66≅7)
3) P= Not the circle or smaller rectangle/ Area of large rectangle
Not the circle or smaller rectangle area
= Area of large rectangle - Area of circle -Area of smaller rectangle
= 120 -4·pi -8 = 120 - (4· 3.14) -8 = 99.4362939 ft²
Area of large rectangle = l·w = 12·10 =120 ft²
P = 99.4362939 /120 ≅ .8286 ≅83% (because .8286·100 =82.86≅83)
what are T-ratio ? explain
answer my question
plz
Answer:
The t-ratio is the estimate divided by the standard error. With a large enough sample, t-ratios greater than 1.96 (in absolute value) suggest that your coefficient is statistically significantly different from 0 at the 95% confidence level. A threshold of 1.645 is used for 90% confidence.
Step-by-step explanation:
Hope it help you.
What is tan 30? A b c d e f
Answer:
try all the square roots and wichever gets to 0.58(rounded) is your answer
Step-by-step explanation:
An engineering consulting firm wanted to evaluate the diameter of rivet heads. The following data represent the diameters (in hundredths of an inch) for a random sample of 25 rivet heads:
(20 pts) 6.81 6.79 6.69 6.59 6.65 6.60 6.74 6.70 6.76 6.84 6.81 6.71 6.66 6.76 6.76 6.77 6.72 6.68 6.71 6.79 6.72 6.72 6.72 6.79 6.83
a. Set up a 95% confidence interval estimate of the average diameter of rivet heads (in hundredths of an inch)
b. Set up a 95% CI estimate of the standard deviation of the diameter rivet heads (in hundredths of an inch)
Answer:
a)CI 95 % = ( 6.7063 ; 6.7593) ( in hundredths of an inch)
b) CI 95 % = ( 0.05 < σ < 0.089 ) ( in hundredths of an inch)
Step-by-step explanation:
From the problem statement, we have a manufacturing process and we we assume a normal distribution, from sample data:
x = 6.7328 and s = 0.0644
a) CI 95 % = ( x ± t(c) * s/√n )
t(c) df = n -1 df = 25 - 1 df = 24
CI = 95 % α = 5 % α = 0.05 α /2 = 0.025
Then from t-student table t(c) = 2.060
s/√n = 0.0644/ √ 25 s/√n = 0.01288
CI 95 % = ( x ± t(c) * s/√n ) = ( 6.7328 ± 2.060*0.01288)
CI 95 % = ( 6.7328 ± 0.02653 )
CI 95 % = ( 6.7063 ; 6.7593) ( in hundredths of an inch)
b) CI 95 % of the variance is:
CI 95 % = ( ( n - 1 ) * s² / χ²₁ - α/₂ ≤ σ² ≤ ( n - 1 )*s² / χ²α/₂ )
( n - 1 ) * s² = ( 25 - 1 ) * (0.0644)² = 24* 0.00414
( n - 1 ) * s² = 0.09936
And from χ² table we look for values of
χ² α/₂ ,df df = 24 and α/2 = 0.025
χ² (0.025,24) = 12.40 and χ²₁ - α/₂ = χ² (0.975, 24)
χ² (0.975, 24) = 39.36
Then
CI 95 % = ( 0.09936 / 39.36 ≤ σ² ≤ 0.09936 / 12.40)
CI 95 % = ( 0.0025 ≤ σ² ≤ 0.0080)
Then for the standard deviation, we take the square root of that interval
CI 95 % = ( 0.05 < σ < 0.089 )
2hr 57min+3hrs42min
Answer:
6 hrs 33 minutes
Step-by-step explanation:
2hr 57min
+3hrs42min
----------------------
5 hrs 99 minutes
But 1 hr = 60 minutes so subtract 60 minutes and add 1 hour
6 hrs 33 minutes
Answer:
6hr 39 min
Step-by-step explanation:
Add both
2hr 57 min
+ 3hr 42 min
5hr 99 min
we know that 1 hr = 60 min
then , 99 min = 1hr 39 min
so, 5hr + 1hr 39min
= 6hr 39 min