Question 1

Yearly Donations
The following data represent the yearly donations (in thousands of dollars) of a sample of 13 benefactors: 26.5, 23.5, 29.7, 24.8, 21.1, 24.3, 20.4, 22.7, 27.2, 23.7, 24.1, 24.8, and 28.2.
-{Yearly Donations Narrative} Compute and interpret the 90th percentile.

Accepted Answer

The answer of Yearly Donations
The following data represent the yearly...

Question 2

Which of the following is a property of the slope, b1?

Accepted Answer

A)  The slope equals one if X and Y have the same variance. 
B)  The slope has the same sign as r, the coefficient of correlation. 
C)  The slope equals one if r equals one. 
D)  All of these choices are true.

Question 3

If the observations are in the millions, a standard deviation of 10 would be considered small.If the observations are all less than 50, a standard deviation of 10 would be considered large.

Accepted Answer

A) True 
 B)False

Question 4

The size of a sample is denoted by the letter ____________________ and the size of a population is denoted by the letter ____________________.

Accepted Answer

The answer of The size of a sample is denoted...

Question 5

Which of the following measures of variability is not sensitive to extreme values?

Accepted Answer

A)  The range 
B)  The standard deviation 
C)  The interquartile range 
D)  The coefficient of variation

Question 6

Ages of Retirees
A sociologist recently conducted a survey of retirees over 65 years of age whose net worth is too high to qualify for Medicaid and who have no private health insurance.The ages of 20 uninsured retirees were as follows: 65, 66, 67, 68, 69, 70, 71, 73, 74, 75, 78, 79, 80, 81, 86, 87, 91, 92, 94, and 97.
-{Ages of Retirees Narrative} What does the value of the third quartile tell you?

Accepted Answer

The answer of Ages of Retirees
A sociologist recently conducted a...

Question 7

According to the Empirical Rule, if the data form a bell shaped normal distribution, approximately ____________________ percent of the observations will be contained within 2 standard deviations around the mean.

Accepted Answer

The answer of According to the Empirical Rule, if the...

Question 8

Hours of Playing Video Games
Suppose that the following data provide the hours of playing video games per week for a sample of 15 high school students in Roanoke, Virginia: 5, 11, 25, 19, 18, 20, 27, 13, 8, 10, 15, 19, 18, 9, and 12.
-{Hours of Playing Video Games Narrative} Determine the location and value of the second quartile.

Accepted Answer

The answer of Hours of Playing Video Games
Suppose that the...

Question 9

Ages of Retirees
A sociologist recently conducted a survey of retirees over 65 years of age whose net worth is too high to qualify for Medicaid and who have no private health insurance.The ages of 20 uninsured retirees were as follows: 65, 66, 67, 68, 69, 70, 71, 73, 74, 75, 78, 79, 80, 81, 86, 87, 91, 92, 94, and 97.
-{Ages of Retirees Narrative} What does the value of the first quartile tell you?

Accepted Answer

The answer of Ages of Retirees
A sociologist recently conducted a...

Question 10

The standard deviation is the positive square root of the variance.

Accepted Answer

A) True 
 B)False

Question 11

Ages of Volunteers
The following data represent the ages in years of a sample of 25 volunteers from a charitable organization: 31, 43, 56, 23, 49, 42, 33, 61, 44, 28, 48, 38, 44, 35, 40, 64, 52, 42, 47, 39, 53, 27, 36, 35, and 20.
-{Ages of Volunteers Narrative} Compute the coefficient of variation and express the number in the appropriate unit.

Accepted Answer

The answer of Ages of Volunteers
The following data represent the...

Question 12

Strip Mall Rent
Monthly rent data in dollars for a sample of 10 stores in a small town in South Dakota are as follows: 220, 216, 220, 205, 210, 240, 195, 235, 204, and 250.
-{Strip Mall Rent Narrative} What is the mode?

Accepted Answer

The answer of Strip Mall Rent
Monthly rent data in dollars...

Question 13

The units for the variance are the same as the units for the original data (for example, feet, inches, etc.).

Accepted Answer

A) True 
 B)False

Question 14

Chebysheff's Theorem applies only to data sets that have a bell shaped distribution.

Accepted Answer

A) True 
 B)False

Question 15

The denominator in the calculation of the sample covariance, cov (x,y), is:

Accepted Answer

A)  n-2 
B)  n - 1 
C)  n 
D)  2n- 1

Question 16

The annual percentage rates of return over the past 10 years for two mutual funds are as shown below.Which fund would you classify as having the higher level of risk?

Accepted Answer

The answer of The annual percentage rates of return over...

Question 17

In a histogram, the proportion of the total area which must be to the left of the median is less than 0.50 if the distribution is negatively skewed.

Accepted Answer

A) True 
 B)False

Question 18

The interquartile range will always exceed that of the range.

Accepted Answer

A) True 
 B)False

Question 19

Expressed in percentiles, the fifth decile is the 50th percentile or the median.

Accepted Answer

A) True 
 B)False

Question 20

The first and second quartiles of a data set can never be equal.

Accepted Answer

A) True 
 B)False

Exam 4: Numerical Descriptive Techniques

Yearly Donations The following data represent the yearly donations (in thousands of dollars) of a sample of 13 benefactors: 26.5, 23.5, 29.7, 24.8, 21.1, 24.3, 20.4, 22.7, 27.2, 23.7, 24.1, 24.8, and 28.2. -{Yearly Donations Narrative} Compute and interpret the 90th percentile.

Which of the following is a property of the slope, b₁?

If the observations are in the millions, a standard deviation of 10 would be considered small.If the observations are all less than 50, a standard deviation of 10 would be considered large.

The size of a sample is denoted by the letter and the size of a population is denoted by the letter .

Which of the following measures of variability is not sensitive to extreme values?

According to the Empirical Rule, if the data form a bell shaped normal distribution, approximately ____________________ percent of the observations will be contained within 2 standard deviations around the mean.

The standard deviation is the positive square root of the variance.

Strip Mall Rent Monthly rent data in dollars for a sample of 10 stores in a small town in South Dakota are as follows: 220, 216, 220, 205, 210, 240, 195, 235, 204, and 250. -{Strip Mall Rent Narrative} What is the mode?

The units for the variance are the same as the units for the original data (for example, feet, inches, etc.).

Chebysheff's Theorem applies only to data sets that have a bell shaped distribution.

The denominator in the calculation of the sample covariance, cov (x,y) , is:

The annual percentage rates of return over the past 10 years for two mutual funds are as shown below.Which fund would you classify as having the higher level of risk?

In a histogram, the proportion of the total area which must be to the left of the median is less than 0.50 if the distribution is negatively skewed.

The interquartile range will always exceed that of the range.

Expressed in percentiles, the fifth decile is the 50th percentile or the median.

The first and second quartiles of a data set can never be equal.