According to the figure showing 2020 GDP for selected countries, how much larger (in percentage terms) is America's GDP than:

The Central Limit Theorem (CLT) states that as the sample size n increases, the sample mean approaches a normal distribution with a mean of μ and a standard deviation of σ/√n.

Therefore, when the number of houses in a population is unknown and a random sample of 48 houses is drawn from it, the mean for the sample sum distribution can be calculated using the CLT as follows:Mean for the sample sum distribution = nμ = 48 * 1670 = 80,160. The standard deviation for the sample sum distribution is given by:σ/√n = 140/√48 ≈ 20.20. Therefore, the sample sum distribution has a mean of 80,160 and a standard deviation of 20.20.To verify this, a histogram can be plotted in Excel using the following steps:Enter the data for the square footage of the 48 houses in column A of the Excel worksheet.Highlight column B and enter the formula =SUM(A1:A48) to sum the data in column A and store the result in column B.Highlight column C and enter the formula =B1/48 to calculate the mean for the sample sum distribution and store it in column C.Highlight column D and enter the formula =140/SQRT(48) to calculate the standard deviation for the sample sum distribution and store it in column D.Highlight columns B, C, and D, and select the Insert tab.Click on the Histogram icon under the Charts group.Select the Histogram chart type, and click OK to generate the histogram.The histogram should show a bell-shaped curve with a mean of 80,160 and a standard deviation of 20.20, indicating that the sample sum distribution is approximately normal.

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To solve the question asked, you can say:  Therefore, the final answers expressions are: E(X) = 5.8; E(X²) = 59.8; V(X) = 21.16 and E(3X + 2) = 20.4

In mathematics, an expression is a set of numbers, variables, and mathematical operations such as addition, subtraction, multiplication, division, and exponentiation that represent quantities or values. Expressions can be as simple as "3 + 4" or as complex as they can contain functions like "sin(x)" or "log(y)" . Expressions can be evaluated by substituting values ​​for variables and performing mathematical operations in the order specified. For example, if x = 2, the expression "3x + 5" is 3(2) + 5 = 11. In mathematics, formulas are often used to describe real-world situations, create equations, and simplify complex math problems. 

To calculate these values, we first need to compute the mean (expected value) and variance of X, which are given by:

E(X) = ∑[x * p(x)]

= 1 * 0.05 + 2 * 0.10 + 4 * 0.35 + 8 * 0.40 + 16 * 0.10

= 5.8

E(X²) = ∑[x² * p(x)]

= 1² * 0.05 + 2² * 0.10 + 4² * 0.35 + 8² * 0.40 + 16² * 0.10

= 59.8

V(X) = E(X²) - [E(X)]²

= 59.8 - 5.8²

= 21.16

E(3X + 2) = 3E(X) + 2

= 3(5.8) + 2

= 20.4

E(3X² + 2) = 3E(X²) + 2

= 3(59.8) + 2

= 179.4

V(3X + 2) = V(3X)

= 9V(X)

= 9(21.16)

= 190.44

E(X + 1) = E(X) + 1

= 5.8 + 1

= 6.8

V(X + 1) = V(X)

= 21.16

Therefore, the final answers are:

E(X) = 5.8

E(X²) = 59.8

V(X) = 21.16

E(3X + 2) = 20.4

E(3X² + 2) = 179.4

V(3X + 2) = 190.44

E(X + 1) = 6.8

V(X + 1) = 21.16

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The statement that gives the most reasonable description of the distribution of quiz scores is "A typical score is within 1 point of the mean." The correct answer is Option D.

The standard deviation (SD) is a measure of the variability of data in a population. Standard deviation is a measure of how much each value differs from the mean (average) value of the data set.

The difference between the highest and lowest values in a dataset is known as the range. It's a quick way to see the data's spread. If the range is big, it implies that the data is more diverse, while if it's small, it implies that the data is more consistent.

The first quartile (Q1) is the value that splits the lowest 25% of a data set from the rest of the data set. If we order the dataset from smallest to largest, the first quartile is the value at the 25th percentile.

The third quartile (Q3) is the value that splits the highest 25% of a data set from the rest of the data set. If we order the dataset from smallest to largest, the third quartile is the value at the 75th percentile.

The sum of all values in a dataset divided by the total number of values in the dataset is known as the mean. The mean, often known as the arithmetic mean, is one of the most basic measures of central tendency in statistics.

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Answer: 28cm²

Step-by-step explanation: To calculate the area of the trapezium, we can use the formula:

Area = (1/2) x (sum of parallel sides) x (height)

In this case, the two parallel sides are 6 cm and 8 cm, and the height is 4 cm.

Plugging in the values, we get:

Area = (1/2) x (6 cm + 8 cm) x 4 cm

Area = (1/2) x 14 cm x 4 cm

Area = 28 cm²

In response to the stated question, we may state that To accommodate scatter plot the provided data on the scatter graph, the grid must be at least 65 squares wide and 62 squares height.

"Scatter plots are graphs that show the association of two variables in a data collection. It is a two-dimensional plane or a Cartesian system that represents data points. The X-axis represents the independent variable or characteristic, while the Y-axis represents the dependent variable. These plots are sometimes referred to as scatter graphs or scatter diagrams."

To plot the supplied data on a scatter graph, we must ensure that the distance and height values are both within the grid.

The given distances are 37, 6, 71, and 28. As a result, the distance axis's minimum and maximum values are 6 and 71, respectively.

Height values are as follows: 61, 32, 94, 48. As a result, the lowest and maximum height axis values are 32 and 94, respectively. To ensure that all of the height values fit on the graph, we need a grid at least 94-32 = 62 squares tall.

To accommodate the provided data on the scatter graph, the grid must be at least 65 squares wide and 62 squares height.

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The estate dealer must sell 13 houses to reach a total commission of GHc6500

Number is a mathematical object used to count, measure, and label. It is an abstract concept that is used in many different contexts. Numbers can be used to represent a variety of different things, including quantities, values, and relationships. They are also used to represent abstract concepts such as time and money. In mathematics, numbers are used to represent sets, operations, and relationships between elements. Numbers play a crucial role in almost all areas of mathematics, from the simple counting to the study of complex equations.

Arithmetic progression is a mathematical process
which involves adding a constant number to a sequence of numbers. In this case, the constant
number is GHc500, and the sequence of numbers is the commission of GHc3750 for the first house
sold.

To find the total number of houses that must be sold to reach a commission of GHc6500, we
need to use arithmetic progression. To do this, we need to calculate the arithmetic mean of the
two numbers GHc3750 and GHc6500. This is done by adding the two numbers and dividing by two.
The arithmetic mean is GHc5125.

We then subtract the initial commission of GHc3750 from the arithmetic mean to find the
increment in the commission for each additional house sold. This gives us the amount of GHc500
for each additional house sold.

To find the total number of houses that must be sold to reach a commission of GHc6500, we
then need to divide the total commission of GHc6500 by the GHc500 increment. This gives us
13 houses. Therefore, the estate dealer must sell 13 houses to reach a total commission of GHc6500.

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The trip from Winston to Carver takes 8 min longer during rush hour, when the average speed is 75 km/h, than in off-peak hours when the average speed is 90 km/h.  the distance between the two towns is  60 km.

Considering the distance between the Winston and carver be "d", since here we got that during off-peak hours, the average speed is 90 km/h. so  by using the formula of  distance which is  distance =speed x time=> d = 90t.

Whereas in rush hour, the average speed is 75 km/h, we also know that the trip takes 8 minutes longer during rush hour.  calling the time it takes to travel during rush hour "t+8/60"( since 8 minutes is 8/60 of an hour). Now using the same formula as before:

d = 75(t + 8/60), since here we have  two equations for d we can equal  them to each other  then we get :

90t = 75(t + 8/60)

=>90t = 75t + 10

=>90t-75t=10

=>t = 2/3

Since during the off-peak hours, it takes 2/3 hours or 40 minutes to travel the distance between Winston and carver. now  using either equation to find the distance we get  

d = 90t = 90(2/3) = 60 km or d = 75(t + 8/60) = 75(2/3 + 8/60) = 60 km

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The area is 49 square yards.

The value of the pooled sample variance is 25 when the first sample has a sample variance of 12 and a second sample has a sample variance of 22.

If a first sample has a sample variance of 12 and a second sample has a sample variance of 22, then the possible values of the pooled sample variance are given by the formula below:

Formula:

pooled sample variance = [(n₁ - 1) s₁² + (n₂ - 1) s₂²] / (n₁ + n₂ - 2)

Where s₁ and s₂ are the sample standard deviations of the first and second samples,

n₁ and n₂ are the sample sizes of the first and second samples, respectively.

Thus, substituting the given values into the formula above, we have pooled sample variance:

= [(n₁ - 1) s₁² + (n₂ - 1) s₂²] / (n₁ + n₂ - 2)

= [(n₁ - 1) 12 + (n₂ - 1) 22] / (n₁ + n₂ - 2)

Checking each of the answer options:

If pooled sample variance is 1, then:

(n₁ - 1) 12 + (n₂ - 1) 22

= (n₁ + n₂ - 2)(1)

= 12n₁ + 22n₂ - 34

= (12n₁ - 12) + (22n₂ - 22)

= 12(n₁ - 1) + 22(n₂ - 1)

The expression on the right-hand side of the equation is a sum of multiples of 12 and 22, and therefore, the expression itself will be a multiple of the greatest common divisor of 12 and 22, which is 2.

Since 34 is not a multiple of 2, the equation cannot be true if the pooled sample variance is 1.

Thus, 1 is not a possible value of the pooled sample variance.

If pooled sample variance is 10, then:

(n₁ - 1) 12 + (n₂ - 1) 22

= (n₁ + n₂ - 2)(10)

= 12n₁ + 22n₂ - 34

= (12n₁ - 12) + (22n₂ - 22)

= 12(n₁ - 1) + 22(n₂ - 1)

The expression on the right-hand side of the equation is a sum of multiples of 12 and 22, and therefore, the expression itself will be a multiple of the greatest common divisor of 12 and 22, which is 2.

Since 34 is not a multiple of 2, the equation cannot be true if the pooled sample variance is 10.

Thus, 10 is not a possible value of the pooled sample variance.

If pooled sample variance is 16, then:

(n₁ - 1) 12 + (n₂ - 1) 22

= (n₁ + n₂ - 2)(16)

= 12n₁ + 22n₂ - 34

= (12n₁ - 12) + (22n₂ - 22)

= 12(n₁ - 1) + 22(n₂ - 1)

The expression on the right-hand side of the equation is a sum of multiples of 12 and 22, and therefore, the expression itself will be a multiple of the greatest common divisor of 12 and 22, which is 2.

Since 34 is not a multiple of 2, the equation cannot be true if the pooled sample variance is 16.

Thus, 16 is not a possible value of the pooled sample variance.

If pooled sample variance is 25, then:

(n₁ - 1) 12 + (n₂ - 1) 22

= (n₁ + n₂ - 2)(25)

= 12n₁ + 22n₂ - 34

= (12n₁ - 12) + (22n₂ - 22)

= 12(n₁ - 1) + 22(n₂ - 1)

The expression on the right-hand side of the equation is a sum of multiples of 12 and 22, and therefore, the expression itself will be a multiple of the greatest common divisor of 12 and 22, which is 2.

Since 46 is a multiple of 2, the equation can be true if the pooled sample variance is 25.

Thus, 25 is a possible value of the pooled sample variance.

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Answer:

Let's call the number "x".

Then, we can write the equation:

7 + 2x = 35

To solve for x, we need to isolate x on one side of the equation.

Subtracting 7 from both sides:

2x = 28

Dividing both sides by 2:

x = 14

Therefore, the number is 14.

Step-by-step explanation:

a. Calculate the expected arrival time:

Given: Time range for arrival of elevator during the next 4.7 minutes is equally likely. The expected value of a discrete random variable is calculated by multiplying each possible value by its probability and adding up the products. So, we can calculate the expected value of the elevator arrival time by integrating the value of the probability density function (which is a straight line in this case) over the given interval. The area under the curve of the probability density function over the entire interval of possible values is 1. The expected arrival time (E) of the elevator is given by: E = (1/4.7) ∫(0 to 4.7) tdt= (1/4.7) [t²/2] [from 0 to 4.7]= 2.3596 minutes or 2.36 minutes (rounded to 2 decimal places)Therefore, the expected arrival time is 2.36 minutes.

b. Probability that an elevator arrives in less than 1.8 minutes:

To calculate the probability of an event happening, we need to find the area under the probability density function (pdf) over the given interval (in this case, less than 1.8 minutes). The pdf is a straight line with a slope of 1/4.7, so the equation of the line is: f(t) = (1/4.7) t. The probability of the elevator arriving in less than 1.8 minutes is: P(T < 1.8) = ∫(0 to 1.8) f(t) dt= ∫(0 to 1.8) (1/4.7) t dt= (1/4.7) [t²/2] [from 0 to 1.8]= 0.56765 (rounded to 4 decimal places)Therefore, the probability that an elevator arrives in less than 1.8 minutes is 0.568 (rounded to 3 decimal places).

c. Probability that the wait for an elevator is more than 1.8 minutes: The probability that the wait for an elevator is more than 1.8 minutes is the complement of the probability that it arrives in less than 1.8 minutes. P(T > 1.8) = 1 - P(T < 1.8) = 1 - 0.56765= 0.43235 (rounded to 3 decimal places)Therefore, the probability that the wait for an elevator is more than 1.8 minutes is 0.432 (rounded to 3 decimal places).

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Answer:

the answer is 2

Step-by-step explanation:

this answer will be 200⁰0000000000⁰00000⁸⁰643367897⁶43677443⁵=5.0

The sample correlation coefficient would be closest to -0.9.

Here's why:

Correlation Coefficient: The correlation coefficient is a statistical measure of the degree of correlation (linear relationship) between two variables. Pearson’s correlation coefficient is the most widely used correlation coefficient to assess the correlation between variables.

Pearson’s correlation coefficient (r) ranges from -1 to 1. A value of -1 denotes a perfect negative correlation, 1 denotes a perfect positive correlation, and 0 denotes no correlation. There is a negative correlation between speed and time. As the speed of the car increases, the time needed to traverse the segment decreases. So, the sample correlation coefficient would be negative.

Since the sample size is large enough, the sample correlation coefficient should be close to the population correlation coefficient. The population correlation coefficient between speed and time should be close to -1, which implies that the sample correlation coefficient should be close to -1.

Therefore, the sample correlation coefficient would be closest to -0.9.

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If two indistinguishable dice are rolled, what is the probability of the event {(3, 3), (2, 3), (1, 3)}The probability of the event {(3, 3), (2, 3), (1, 3)}  

If two indistinguishable dice are rolled, it is 3/36 or 1/12.

Explanation: Indistinguishable dice are dice that appear identical to one another but do not have unique markings. As a result, indistinguishable dice will have the same number of faces, but the values on each face will be identical.

The total number of possible outcomes is 6 * 6 = 36 because there are six possible outcomes for each roll of a single die.

The probability of rolling the numbers (3, 3), (2, 3), or (1, 3) can be determined as follows: 3/36 or 1/12

For each die, there are six possible outcomes, so there are 6*6, or 36 possible outcomes for two dice.

Because (3, 3), (2, 3), and (1, 3) are the only possible ways to obtain a 3 on one of the dice and a 3, 2, or 1 on the other, the probability is 3/36 or 1/12.

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Answer: add and image

Step-by-step explanation:

not full question

Answer:

83219083219389238293829381293

Step-by-step explanation:

according to my calculations i am not smart

Answer:

Step-by-step explanation:

100 students all together.

50+70=120....so 20 must like both.

Answer:

x = 45.

Step-by-step explanation:

We know the full angle of this is 180 degrees.

Given: (2x+45) + x = 180

First, collect like terms ( in this case 2x and x, 180 and 45 )

2x + x = 180 - 45

Then calculate:

3x = 135. ( Divide both sides by 3 )

x = 45

The angle of elevation of the sun is approximately 22.6 degrees.

The partnerships between the sides and angles of triangles are the subject of the mathematical discipline of trigonometry. It is used exhaustively in fields such as physics, engineering, and assessing.

In a right triangle, the side opposite the right angle is called the hypotenuse, while the other two sides are called the legs.

Given that, 7.6 m flagpole casts an 18.2 m shadow.

Using trigonometric ratio we have:

tan(θ) = h / s

Substituting the values:

tan(θ) = 7.6 / 18.2

tan(θ) ≈ 0.417

θ ≈ 22.6°

Hence, the angle of elevation of the sun is approximately 22.6 degrees.

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By using differentials to estimate the maximum error when measuring the volume of the sphere if the possible error in measuring the radius is 0.5. It will be 32,572.03 in³. Which is option (d).

The possible error in measuring the radius of the sphere is 0.5 in

The formula for the volume of a sphere is given by V(r) = 4/3πr³

The volume of the sphere when r=72 in is given by V(72) = 4/3π(72)³

When r= 72 + 0.5 in= 72.5 in, the volume of the sphere can be calculated using the formula:

V(72.5) = 4/3π(72.5)³

The difference between these two volumes, V(72) and V(72.5), gives us the maximum error while measuring the volume of a sphere. It can be calculated as follows:

V(72.5) - V(72) = 4/3π(72.5)³ - 4/3π(72)³= 4/3π [ (72.5)³ - (72)³ ]= 4/3π [ (72 + 0.5)³ - 72³ ]= (4/3)π [ 3(72²)(0.5) + 3(72)(0.5²) + 0.5³ ]≈ (4/3)π [ 777.5 ]= 3.28 × 10⁴ in³

Therefore, the maximum error while measuring the volume of a sphere with a radius of 72 in, where the possible error in measuring the radius is 0.5 in, is approximately 3.28 × 10⁴ in³ or 32,572.03 in³. Therefore coorect option is (D).

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Answer:

Jack's company needs to sell 3540 cards this year in order to make their target profit.

Step-by-step explanation:

Given the average profit per card last year was £1.50, and the average profit per card is 22% lower this year, this year's average profit per card will be:

[tex]\begin{aligned}\implies \sf Average\;profit\;per\;card&= \£1.50 - (22\% \;\text{of}\; \£1.50)\\&=\£1.50-0.22 \times \£1.50\\&=\£1.50-\£0.33\\&=\£1.17\end{aligned}[/tex]

Given the total profit Jack is aiming for this year is 18% more than last year's profit of £3510, this year's target profit is:

[tex]\begin{aligned}\implies \sf Target\;profit&=\£3510 + (18\%\;\text{of}\;\£3510)\\&=\£3510 + 0.18 \times \£3510\\&=\£3510 + \£631.80\\&=\£4141.80\end{aligned}[/tex]

To calculate how many cards Jack's company needs to sell to make this target profit, divide the total target profit by the average profit per card:

[tex]\begin{aligned}\implies \sf Number\;of\;cards&=\dfrac{4141.80}{1.17}\\\\&=3540\end{aligned}[/tex]

Therefore, Jack's company needs to sell 3540 cards this year in order to make their target profit.

The error is the substitution of coordinates. Coordinates are ordered pairs of points that help us locate any point in a 2D plane or 3D space.

Cartesian coordinates, also known as the coordinates of a point in a 2D plane, are two integers, or occasionally a letter and a number, that identifies a specific point's precise location on a grid. This grid is referred to as a coordinate plane.

The distance between two points A(x₁, y₁) and B(x₂, y₂) is given by

[tex]AB = \sqrt{(x_{1} , x_{2})^{2} + (y_{1} - y_{2})^{2} }[/tex]

Observe that the x-coordinate of B is subtracted from the x-coordinate of A. This goes with the y-coordinates.

Therefore, the error is the substitution of coordinates.

The correct computation is

[tex]AB = \sqrt{(6-1)^{2} + [2 - (-4)]^{2} }[/tex]

[tex]= \sqrt{5^{2} + 6^{2} }[/tex]

[tex]= \sqrt{25 + 36} \\[/tex]

[tex]= \sqrt{61}[/tex]

≈ 7.81

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The complete question is as follows:

Describe and correct the error in finding the distance between A(6, 2) and B(1, -4). AB = √[(6 - 2)² + {2 - (-4)}²] = √(4² + 5²) = √(16 + 25) = √41 ≈ 6.4.

Check the picture below.

so let's get the chord using the pythagorean theorem hmmm using sine

[tex]\sin(35^o )=\cfrac{\stackrel{opposite}{x}}{\underset{hypotenuse}{5}}\implies 5\sin(35^o )=x\implies 2.87\approx x~\hfill \underset{ PQ }{\stackrel{ 2.87+2.87 }{\approx \text{\LARGE 5.74}}}[/tex]

now let's get the arc

[tex]\textit{arc's length}\\\\ s = \cfrac{\theta \pi r}{180} ~~ \begin{cases} r=radius\\ \theta =\stackrel{degrees}{angle}\\[-0.5em] \hrulefill\\ \theta =70\\ r=5 \end{cases}\implies s=\cfrac{(70)\pi (5)}{180}\implies s\approx \text{\LARGE 6.11}[/tex]

and the perimeters, keeping in mind that for the sector is just the arc plus the radii, and for the segment is simply the arc plus the chord.

[tex]\stackrel{ \textit{sector's perimeter} }{5+5+6.11 ~~ \approx ~~} \text{\LARGE 16.11}\hspace{5em}\stackrel{ \textit{segment's perimeter} }{5.74+6.11 ~~ \approx ~~} \text{\LARGE 11.85}[/tex]

The function is constant from approximately x = -4 to x = -3 and from approximately x = -1 to x = 1. So, the constant intervals are (-4, -3) and (-1, 1)

A function, which produces one output from a single input, is an illustration of a rule. The picture was obtained from Alex Federspiel. The equation y=x2 serves as an example of this.

a) We can see that the function is increasing from approximately x = -3 to x = -1 and from approximately x = 1 to x = 2.5. So, the increasing intervals are (-3,-1) and (1, 2.5)

(b) We can see that the function is decreasing from approximately x = -2 to x = -0.5 and from approximately x = 3 to x = 4. So, the decreasing intervals are (-2, -0.5) and (3, 4)

(c) We can see that the function is constant from approximately x = -4 to x = -3 and from approximately x = -1 to x = 1. So, the constant intervals are (-4, -3) and (-1, 1)

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There are 18 possible outcomes for Bonny to pick a card and spin a rolling cube at random.

There are a total of 6 outcomes for the rolling cube and 3 outcomes for picking a card. To find the total number of outcomes, we can use the multiplication rule of counting:

Total number of outcomes = number of outcomes for picking a card x number of outcomes for rolling a cube

Total number of outcomes = 3 x 6 = 18

Therefore, there are 18 possible outcomes for Bonny to pick a card and spin a rolling cube at random.

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Explanation:

2n is greater than 20, so 2n > 20. This solves to n > 10 after dividing both sides by 2. That inequality is the same as 10 < n.

5n is less than 60. It leads to 5n < 60. That solves to n < 12 after dividing both sides by 5.

To summarize:

Combine 10 < n with n < 12 to write a compound inequality:

10 < n < 12

The value n is between 10 and 12. We exclude each endpoint.

The only possible whole number that works here is n = 11

The probability that a person chosen at random at age 40 or older has only completed high school is 0.2912.

Probability is the chance or likelihood that something will occur. It is quantified using numbers, ranging from 0 (no chance) to 1 (certainty). It also helps us to draw conclusions about the chances of something happening based on the available data.

The total number of people who have only completed high school

=(5394)

the total number of people in the age group 40 and over =(18521)

By dividing both the data, we get

5394/18521= 0.2912

From the given data in the table, we can calculate the probability that a person chosen at random at age 40 or older has only completed high school.

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Answer:

  3. 79.9 mm²

  4. 6.4 in

  5. 177.5 mi²

  6. 60.3°

Step-by-step explanation:

Given various quadrilaterals and their dimensions, you want to find missing dimensions.

In all cases, one or more area formulas and trig relations are involved. The trig relations are summarized by the mnemonic SOH CAH TOA. The relevant relation for these problems is ...

  Tan = Opposite/Adjacent

It is also useful to know that 1/tan(x) = tan(90°-x).

The formula for the area of a trapezoid is ...

  A = 1/2(b1 +b2)h

The relevant formula here for the area of a parallelogram is ...

  A = bs·sin(α) . . . . . where α is the angle between sides of length b and s

Using the area formula above, we find the area to be ...

  A = (21 mm)(9 mm)·sin(155°) ≈ 79.9 mm²

The area is about 79.9 square mm.

The given figure shows two unknowns. We can write equations for these using the area formula and using a trig relation.

If we draw a vertical line through the vertex of the marked angle, the base of the triangle to the right of it is (b2-4). The acute angle at the top of that right triangle is (121°-90°) = 31°. The tangent relation tells us ...

  tan(31°) = (b2 -4)/h   ⇒   h = (b2 -4)/tan(31°)

Using the area formula we have ...

  A = 1/2(b2 +4)h

and substituting for A and h, we get ...

  20.8 = 1/2(b2 +4)(b2 -4)/tan(31°)

  2·tan(31°)·20.8 = (b2 +4)(b2 -4) = (b2)² -16 . . . . . multiply by 2tan(31°)

  (b2)² = 2·tan(31°)·20.8 +16 . . . . . . . add 16

  b2 = √(2·tan(31°)·20.8 +16) ≈ 6.4 . . . . . . take the square root

Base 2 of the trapezoid is about 6.4 inches.

To find the area, we need to know the height of the trapezoid. To find the height we can solve a triangle problem.

If we draw a diagonal line parallel to the right side through the left end of the top base, we divide the figure into a triangle on the left and a parallelogram on the right. The triangle has a base width of 10 mi, and base angles of 60° and 75°.

Drawing a vertical line through the top vertex of this triangle divides it into two right triangles of height h. The top angle is divided into two angles, one being 90°-60° = 30°, and the other being 90°-75° = 15°. The bases of these right triangles are now ...

and their sum is 10 mi.

The height h can now be found to be ...

  h·tan(30°) +h·tan(15°) = 10

  h = 10/(tan(30°) +tan(15°))

Back to our formula for the area of the trapezoid, we find it to be ...

  A = 1/2(b1 +b2)h = 1/2(20 +10)(10/(tan(30°) +tan(15°)) ≈ 177.5

The area of the trapezoid is about 177.5 square miles.

The final formula we used for problem 5 can be used for problem 6 by changing the dimensions appropriately.

  A = 1/2(b1 +b2)(b1 -b2)/(tan(90-x) +tan(90-x))

  112 = 1/2(20+12)(20-12)/(2·tan(90-x)) = (20² -12²)·tan(x)/4

  tan(x) = 4·112/(20² -12²)

  x = arctan(4·112/(20² -12²)) = arctan(7/4) ≈ 60.3°

Angle x° in the trapezoid is about 60.3°.

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Additional comment

There is no set "step by step" for solving problems like these. In general, you work from what you know toward what you don't know. You make use of area and trig relations as required to create equations you can solve for the missing values. There are generally a number of ways you can go at these.

A nice scientific calculator has been used in the attachment for showing the calculations. A graphing calculator can be useful for solving any system of equations you might write.

The second attachment shows a graphing calculator solution to problem 5, where we let y = area, and x = the portion of the bottom base that is to the left of the top base. Area/15 represents the height of the trapezoid. This solution also gives an area of 177.5 square miles.

The values of x which satisfies the fractional inequality (x - 1) / (2 - x) ≥ 0 is x ≥ 1

(x - 1) / (2 - x) ≥ 0

This is a fractional inequality whose numerator is (x - 1) and the denominator is (2 - x)

(x - 1) / (2 - x) ≥ 0

cross product

(x - 1) ≥ 0 × (2 - x)

(x - 1) ≥ 0

x - 1 ≥ 0

Add 1 to both sides

x ≥ 1

Therefore, x ≥ 1 satisfies the inequality.

Read more on inequality:

https://brainly.com/question/25275758

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If the shape is made up of one half-circle attached to an equilateral triangle with side lengths 20 inches then, the perimeter of the shape is 91.4 inches.

To find the perimeter of the shape, we need to know the length of the curved boundary (the circumference of the half-circle) and the length of the straight boundary (the perimeter of the equilateral triangle).

The radius of the half-circle is half the length of the side of the equilateral triangle, which is 10 inches. Therefore, the circumference of the half-circle is:

C = πr = π(10) = 31.4 inches.

The perimeter of the equilateral triangle is 3 times the length of one side, which is 20 inches. Therefore, the perimeter of the triangle is:

P = 3s = 3(20) = 60 inches

Finally, the perimeter of the entire shape is the sum of the lengths of the curved and straight boundaries:

Perimeter = C + P = 31.4 + 60 = 91.4 inches.

To know more about equilateral triangle

brainly.com/question/3461022

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Complete Question

This shape is made up of one half-circle attached to a square with side lengths 11 inches. Find the perimeter of the shape.

You can use 3.14 as an approximation for π. help i don't know it.