Question 1

Suppose a distribution has a mean of 80 and standard deviation of 10.It is found that 84 percent of the values in the data set lie between 70 and 90.This implies that the distribution is not bell-shaped.

Accepted Answer

The answer of Suppose a distribution has a mean of...

Question 2

Consider a situation involving two populations where population 1 is known to have a higher coefficient of variation than population 2.In this situation,we know that population 1 has a higher standard deviation than population 2.

Accepted Answer

The coefficient of variation is a measure of relative variability that is calculated as the standard deviation divided by the mean. A higher coefficient of variation in population 1 compared to population 2 indicates that population 1 has greater variability relative to its mean, not necessarily a higher standard deviation in absolute terms.

Question 3

Consider the following sample data:  For these data the median is:
A)7.5.
B)3.5.
C)10.
D)None of the above.

Accepted Answer

The answer of Consider the following sample data:  For...

Question 4

A small company has 7 employees.The numbers of years these employees have worked for this company are shown as follows:  Based upon this information,the median number of years that employees have been with this company is:
A)9 years.
B)16 years.
C)10 years.
D)14 years.

Accepted Answer

The answer of A small company has 7 employees.The numbers...

Question 5

Acme Taxi has two taxi cabs.The manager tracks the daily revenue for each cab.Over the past 20 days,Cab A has averaged $76.00 per night with a standard deviation equal to $11.00.Cab B has averaged $200.00 per night with a standard deviation of $18.00.Based on this information,Cab B has the greatest relative variation.

Accepted Answer

Relative variation is calculated as the standard deviation divided by the mean. For Cab A, the relative variation is $11.00 / $76.00 ≈ 0.145. For Cab B, it is $18.00 / $200.00 = 0.09. Therefore, Cab A has the greater relative variation.

Question 6

A small company has 7 employees.The numbers of years these employees have worked for this company are shown as follows:  Based upon this information,the mean number of years that employees have been with this company is:
A)16.
B)  .
C)8.40.
D)10.

Accepted Answer

The answer of A small company has 7 employees.The numbers...

Question 7

A small company has 7 employees.The numbers of years these employees have worked for this company are shown as follows:  Based upon this information,the mode number of years that employees have been with this company is:
A)16.
B)2.
C)9.
D)10.

Accepted Answer

The answer of A small company has 7 employees.The numbers...

Question 8

Acme Taxi has two taxi cabs.The manager tracks the daily revenue for each cab.Over the past 20 days,Cab A has averaged $76.00 per night with a standard deviation equal to $11.00.Cab B has averaged $200.00 per night with a standard deviation of $18.00.Based on this information,the coefficient of variation for Cab B is 9 percent.

Accepted Answer

The coefficient of variation is equal to the standard deviation divided by the mean, multiplied by 100 percent. For Cab B, the coefficient of variation is (18/200)*100 = 9 percent. Therefore, the statement is true.

Question 9

The distribution of bankcard balances for customers is highly right-skewed with a mean of $1,100 and a standard deviation equal to $250.Based on this information,approximately 68 percent of the customers will have bank balances between $850 and $1,350.

Accepted Answer

Since the distribution is highly right-skewed, it is not possible to use the empirical rule (68% of data falls within one standard deviation of the mean) to estimate the percentage of customers with balances between $850 and $1,350. A different approach, such as using a z-score and the normal distribution, would be needed to make this estimation.

Question 10

Based on the empirical rule we can assume that all distributions have approximately 95 percent of the values within ± 2 standard deviations of the mean.

Accepted Answer

The empirical rule, also known as the 68-95-99.7 rule, states that approximately 68% of the values in a distribution are within ± 1 standard deviation of the mean, approximately 95% of the values are within ± 2 standard deviations of the mean, and approximately 99.7% of the values are within ± 3 standard deviations of the mean. Therefore, the statement is true.

Question 11

Which of the following statements is true?
A)The mean of a population will always be larger than the population standard deviation.
B)The mean of the population will generally be larger than the mean of the sample selected from that population.
C)The population mean and a sample mean for a sample selected from that population will usually be different values.
D)The population mean and sample mean will always be identical.

Accepted Answer

The population mean and a sample mean for a sample selected from that population will usually be different values due to sampling variability. The other statements are not true in general.

Question 12

Based on the empirical rule we can expect about 95 percent of the values in bell-shaped distribution to be within one standard deviation of the mean.

Accepted Answer

According to the empirical rule, about 68% of the values in a bell-shaped distribution are within one standard deviation of the mean, while about 95% are within two standard deviations.

Question 13

A population measure,such as the population mean,is called a:
A)statistic.
B)parameter.
C)prime number.
D)sample value.

Accepted Answer

A population measure is a parameter, while a sample measure is a statistic. Choice A, C and D are incorrect as they do not relate to population measures.

Question 14

Consider the following sample data:  For these data the sample mean is:
A)8.
B)10.
C)3.
D)12.

Accepted Answer

It is not possible to calculate the mean of this sample data as it does not consist of numerical values. Therefore, the answer cannot be A, C, or D.

Question 15

The distribution of dollars paid for car insurance by car owners in a major east coast city is bell-shaped with a mean equal to $750 every six months and a standard deviation equal to $100.Based on this information we can use Tchebysheff's theorem to determine the conservative percentage of car owners that will pay between $550 and $950 for car insurance.

Accepted Answer

The answer of The distribution of dollars paid for car...

Question 16

The credit card balances for customers at State Bank and Trust has a mean equal to $800 and a standard deviation equal to $60.00.Kevin Smith's balance is $1,352.Based on this,his standardized value is 9.20.

Accepted Answer

The answer of The credit card balances for customers at...

Question 17

If a business manager selected a sample of customers and computed the mean income for this sample of customers,she has computed:
A)a statistic.
B)an ordinal value.
C)a nominal value.
D)a parameter.

Accepted Answer

The computation of mean income for a sample of customers is an example of a statistic because it is a numerical measurement based on a subset of the population (the sample), rather than the entire population.

Question 18

The most frequently used measure of central tendency is:
A)median.
B)mean.
C)mode.
D)middle value.

Accepted Answer

The mean is the most frequently used measure of central tendency as it takes into account all values in a dataset and is commonly used in statistical analysis.

Question 19

A major automobile maker has two models of sedans.The first model has been shown to get an average of 27 mpg on the highway with a standard deviation equal to 5 mpg.The second model gets 33 mpg on average with a standard deviation of 8 mpg.Based on this information the first car model is relatively more variable than the second car model.

Accepted Answer

The coefficient of variation (CV), which is the standard deviation divided by the mean, is used to compare variability relative to the mean between datasets. For the first model, CV = 5 / 27. For the second model, CV = 8 / 33. The second model has a higher CV, indicating it is relatively more variable.

Question 20

A sample of people who have attended a college football game at your university has a mean = 3.2 members in their family.The mode number of family members is 2 and the median number is 2.0.Based on this information:
A)the population mean exceeds 3.2.
B)the distribution is bell-shaped.
C)the distribution is right-skewed.
D)the distribution is left-skewed.

Accepted Answer

The fact that the mode (2) is less than the mean (3.2) suggests that there are some larger values pulling the mean up, making the distribution right-skewed. A bell-shaped distribution would have the mean, mode, and median all be the same or close to it.

Quiz 3: Describing Data Using Numerical Measures

Suppose a distribution has a mean of 80 and standard deviation of 10.It is found that 84 percent of the values in the data set lie between 70 and 90.This implies that the distribution is not bell-shaped.

Consider a situation involving two populations where population 1 is known to have a higher coefficient of variation than population 2.In this situation,we know that population 1 has a higher standard deviation than population 2.

Consider the following sample data: For these data the median is:

A small company has 7 employees.The numbers of years these employees have worked for this company are shown as follows: Based upon this information,the median number of years that employees have been with this company is:

A small company has 7 employees.The numbers of years these employees have worked for this company are shown as follows: Based upon this information,the mean number of years that employees have been with this company is:

A small company has 7 employees.The numbers of years these employees have worked for this company are shown as follows: Based upon this information,the mode number of years that employees have been with this company is:

The distribution of bankcard balances for customers is highly right-skewed with a mean of $1,100 and a standard deviation equal to $250.Based on this information,approximately 68 percent of the customers will have bank balances between $850 and $1,350.

Based on the empirical rule we can assume that all distributions have approximately 95 percent of the values within ± 2 standard deviations of the mean.

Which of the following statements is true?

Based on the empirical rule we can expect about 95 percent of the values in bell-shaped distribution to be within one standard deviation of the mean.

A population measure,such as the population mean,is called a:

Consider the following sample data: For these data the sample mean is:

The credit card balances for customers at State Bank and Trust has a mean equal to $800 and a standard deviation equal to $60.00.Kevin Smith's balance is $1,352.Based on this,his standardized value is 9.20.

If a business manager selected a sample of customers and computed the mean income for this sample of customers,she has computed:

The most frequently used measure of central tendency is:

A sample of people who have attended a college football game at your university has a mean = 3.2 members in their family.The mode number of family members is 2 and the median number is 2.0.Based on this information: