Assistance is available for AMU MATH 120 Intro to statistics quiz 2 week 2-2a American Military University at domyclass

Table of Contents

#### MATH 120 AMU Quiz 2 question 1

Find the mean, median, and mode of the data set.

9 6 8 6 7

mean (Enter a number.)

median (Enter an exact number.)

mode (Enter an exact number.)

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#### MATH 120 AMU Quiz 2 question 2

question In this problem, we explore the effect on the mean, median, and mode of adding the same number to each data value. Consider the data set 2, 2, 3, 6, 10.

(a) Compute the mode, median, and mean. (For each answer, enter a number.)

mode

median

mean

(b) Add 3 to each of the data values. Compute the mode, median, and mean. (For each answer, enter a number.)

mode

median

mean

(c) Compare the results of parts (a) and (b). In general, how do you think the mode, median, and mean are affected when the same constant is added to each data value in a set?

Adding the same constant c to each data value results in the mode, median, and mean increasing by c units.

Adding the same constant c to each data value results in the mode, median, and mean decreasing by c units.

Adding the same constant c to each data value results in the mode, median, and mean remaining the same.

There is no distinct pattern when the same constant is added to each data value in a set.

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#### MATH 120 AMU Quiz 2 question 3

Find the weighted average of a data set where 20 has a weight of 2, 30 has a weight of 5, and 40 has a weight of 3. (Enter an exact number.)

#### MATH 120 AMU Quiz 2 question 4

Consider the data set.

2, 3, 4, 6, 8

(a) Find the range. (Enter an exact number.)

(b) Use the defining formula to compute the sample standard deviation s. (Enter a number. Round your answer to two decimal places.)

(c) Use the defining formula to compute the population standard deviation σ. (Enter a number. Round your answer to two decimal places.)

#### MATH 120 AMU Quiz 2 question 5

Given the sample data.

x: 21, 19, 15, 32, 27

(a) Find the range. (Enter an exact number.)

(b) Verify that Σx = 114 and Σx2 = 2,780. (For each answer, enter an exact number.)

Σx =

Σx2 =

(c) Use the results of part (b) and appropriate computation formulas to compute the sample variance s2 and sample standard deviation s. (For each answer, enter a number. Round your answers to two decimal places.)

s2 =

s =

(d) Use the defining formulas to compute the sample variance s2 and sample standard deviation s. (For each answer, enter a number. Round your answers to two decimal places.)

s2 =

s =

(e) Suppose the given data comprise the entire population of all x values. Compute the population variance σ2 and population standard deviation σ. (For each answer, enter a number. Round your answers to two decimal places.)

σ2 =

σ =

#### MATH 120 AMU Quiz 2 question 6

Consider sample data with x bar = 8 and s = 4. (For each answer, enter an exact number.)

(a) Compute the coefficient of variation (as a percent).

%

(b) Compute a 75% Chebyshev interval around the sample mean.

Lower Limit

Upper Limit

#### MATH 120 AMU Quiz 2 question 7

Consider the following ordered data.

4 7 7 8 9 9 10 11 12

(a) Find the low, Q1, median, Q3, and high. (For each answer, enter a number.)

low

Q1

median

Q3

high

(b) Find the interquartile range. (Enter a number.)

(c) Make a box-and-whisker plot. (Select the correct graph.)

#### MATH 120 AMU Quiz 2 question 8

How much should a healthy Shetland pony weigh? Let x be the age of the pony (in months), and let y be the average weight of the pony (in kilograms).

x 3 6 12 20 24

y 60 95 140 170 189

(a) Make a scatter diagram of the data and visualize the line you think best fits the data. (Submit a file with a maximum size of 1 MB.)

(b) Would you say the correlation is low, moderate, or strong?

low

moderate

strong

Would you say the correlation is positive or negative?

positive

negative

(c) Use a calculator to verify that Σ(x) = 65, Σ(x2) = 1165, Σ(y) = 654, Σ(y2) = 96,846, and Σ(x y) = 10,366.

Compute r. (Enter a number. Round your answer to three decimal places.)

As x increases from 3 to 24 months, does the value of r imply that y should tend to increase or decrease? Explain your answer.

Given our value of r, y should tend to increase as x increases.

Given our value of r, y should tend to remain constant as x increases.

Given our value of r, y should tend to decrease as x increases.

Given our value of r, we can not draw any conclusions for the behavior of y as x increases.