Question 1

VenalCo Market Research surveyed 50 individuals who recently purchased a certain CD, revealing the age distribution shown below. Which statement is least defensible?

Accepted Answer

A) The mean age probably exceeds the median age. 
B) The mode would be a reasonable measure of center. 
C) The data are somewhat skewed to the left. 
D) The CD is unlikely to appeal to retirees. 
A) The mean age probably exceeds the median age. 
B) The mode would be a reasonable measure of center. 
C) The data are somewhat skewed to the left. 
D) The CD is unlikely to appeal to retirees. A

Question 2

In Tokyo, construction workers earn an average of ×420,000 (yen) per month with a standard deviation of ×20,000, while in Hamburg, Germany, construction workers earn an average of €3,200 (euros) per month with a standard deviation of €57. Who is earning relatively more, a worker making ×460,000 per month in Tokyo or one earning €3,300 per month in Hamburg?

Accepted Answer

A) The workers are the same in relative terms. 
B) The Tokyo worker is relatively better off. 
C) The Hamburg worker is relatively better off. 
A) The workers are the same in relative terms. 
B) The Tokyo worker is relatively better off. 
C) The Hamburg worker is relatively better off. B

Question 3

Which is true of skewness?

Accepted Answer

A) In business data, positive skewness is unusual. 
B) In a negatively skewed distribution, the mean is likely to exceed the median. 
C) Skewness often is evidenced by one or more outliers. 
D) The expected range of Excel's skewness coefficient increases as n increases. 
A) In business data, positive skewness is unusual. 
B) In a negatively skewed distribution, the mean is likely to exceed the median. 
C) Skewness often is evidenced by one or more outliers. 
D) The expected range of Excel's skewness coefficient increases as n increases. C

Question 4

The sum of the deviations around the mean is always zero.

Accepted Answer

A) True 
 B)False

Question 5

The following frequency distribution shows the amount earned yesterday by employees of a large Las Vegas casino. Estimate the mean daily earnings. $$\begin{array} { c c } 
\text { Earnings (dollars) } & \text { Frequency } \
50 < 75 & 10 \
75 < 100 & 15 \
100 < 125 & 60 \
125 < 150 & 40 \
150 < 175 & 10
\end{array}$$

Accepted Answer

A) $112.50 
B) $125.01 
C) $105.47 
D) $117.13 
A) $112.50 
B) $125.01 
C) $105.47 
D) $117.13

Question 6

The midrange is not greatly affected by outliers.

Accepted Answer

A) True 
 B)False

Question 7

Five homes were recently sold in Oxnard Acres. Four of the homes sold for $400,000, while the fifth home sold for $2.5 million. Which measure of central tendency best represents a typical home price in Oxnard Acres?

Accepted Answer

A) The mean or median. 
B) The median or mode. 
C) The mean or mode. 
D) The midrange or mean. 
A) The mean or median. 
B) The median or mode. 
C) The mean or mode. 
D) The midrange or mean.

Question 8

A trimmed mean may be preferable to a mean when a data set has extreme values.

Accepted Answer

A) True 
 B)False

Question 9

John scored 85 on Prof. Hardtack's exam (Q1 = 40 and Q3 = 60). Based on the fences, which is correct?

Accepted Answer

A) John is an extreme outlier. 
B) John is an outlier. 
C) John is not an outlier. 
D) John is in the 85th percentile. 
A) John is an extreme outlier. 
B) John is an outlier. 
C) John is not an outlier. 
D) John is in the 85th percentile.

Question 10

A national survey showed that most commuter cars contain only the driver. Hungry for a story, a campus newspaper reporter asked five randomly chosen commuter students how many occupants, including the driver, rode to school in their cars. Their responses were 1, 1, 1, 1, and 6. The next day a story appeared in the paper headlined "University Commuters Double National Average Ridership." Is this a reasonable assessment of central tendency? How would you characterize the variability of the sample?

Accepted Answer

The mean is 2, median is 1, an

Question 11

A survey of 10 randomly chosen drivers showed the following number of persons per car, including the driver: 1, 5, 1, 5, 2, 1, 1, 1, 2, 1. Describe the center, variability, and skewness for this sample.

Accepted Answer

@#IMG-DLM& Mean is 2, median i

Question 12

A positive kurtosis coefficient in Excel indicates a leptokurtic condition in a distribution.

Accepted Answer

A) True 
 B)False

Question 13

A platykurtic distribution is more sharply peaked (i.e., thinner tails) than a normal distribution.

Accepted Answer

A) True 
 B)False

Question 14

A population consists of the following data: 7, 11, 12, 18, 20, 22, 25. The population variance is:

Accepted Answer

A) 6.07. 
B) 36.82. 
C) 5.16. 
D) 22.86. 
A) 6.07. 
B) 36.82. 
C) 5.16. 
D) 22.86.

Question 15

A sample of customers from Barnsboro National Bank shows an average account balance of $315 with a standard deviation of $87. A sample of customers from Wellington Savings and Loan shows an average account balance of $8350 with a standard deviation of $1800. Which statement about account balances is correct?

Accepted Answer

A) Barnsboro Bank has more variation. 
B) Wellington S&L has more variation. 
C) Both have the same variation. $\overline { X ^ { * } }$ $\overline { X ^ { * } }$ 
A) Barnsboro Bank has more variation. 
B) Wellington S&L has more variation. 
C) Both have the same variation. $\overline { X ^ { * } }$ $\overline { X ^ { * } }$

Question 16

If Q1 = 150 and Q3 = 250, the upper fences (inner and outer) are:

Accepted Answer

A) 450 and 600. 
B) 350 and 450. 
C) 400 and 550. 
D) impossible to determine without more information. 
A) 450 and 600. 
B) 350 and 450. 
C) 400 and 550. 
D) impossible to determine without more information.

Question 17

In calculating the sample variance, the sum of the squared deviations around the mean is divided by n - 1 to avoid underestimating the unknown population variance.

Accepted Answer

A) True 
 B)False

Question 18

One disadvantage of the range is that:

Accepted Answer

A) only extreme values are used in its calculation. 
B) it is expressed in different units than the mean. 
C) it does not exist for some data sets. 
D) it is undefined if any X values are 0 or negative. 
A) only extreme values are used in its calculation. 
B) it is expressed in different units than the mean. 
C) it does not exist for some data sets. 
D) it is undefined if any X values are 0 or negative.

Question 19

If the standard deviations of two samples are the same, so are their coefficients of variation.C.V.

Accepted Answer

A) True 
 B)False

Question 20

If there are 20 data values, the median will be halfway between two data values.

Accepted Answer

A) True 
 B)False

VenalCo Market Research surveyed 50 individuals who recently purchased a certain CD, revealing the age distribution shown below. Which statement is least defensible?

Which is true of skewness?

The sum of the deviations around the mean is always zero.

The following frequency distribution shows the amount earned yesterday by employees of a large Las Vegas casino. Estimate the mean daily earnings. Earnings (dollars) Frequency 50<75 10 75<100 15 100<125 60 125<150 40 150<175 10

The midrange is not greatly affected by outliers.

Five homes were recently sold in Oxnard Acres. Four of the homes sold for $400,000, while the fifth home sold for $2.5 million. Which measure of central tendency best represents a typical home price in Oxnard Acres?

A trimmed mean may be preferable to a mean when a data set has extreme values.

John scored 85 on Prof. Hardtack's exam (Q₁ = 40 and Q₃ = 60). Based on the fences, which is correct?

A survey of 10 randomly chosen drivers showed the following number of persons per car, including the driver: 1, 5, 1, 5, 2, 1, 1, 1, 2, 1. Describe the center, variability, and skewness for this sample.

A positive kurtosis coefficient in Excel indicates a leptokurtic condition in a distribution.

A platykurtic distribution is more sharply peaked (i.e., thinner tails) than a normal distribution.

A population consists of the following data: 7, 11, 12, 18, 20, 22, 25. The population variance is:

If Q₁ = 150 and Q₃ = 250, the upper fences (inner and outer) are:

In calculating the sample variance, the sum of the squared deviations around the mean is divided by n - 1 to avoid underestimating the unknown population variance.

One disadvantage of the range is that:

If the standard deviations of two samples are the same, so are their coefficients of variation.C.V.

If there are 20 data values, the median will be halfway between two data values.

Overview of Statistics

Data Collection

Describing Data Visually

Probability

Discrete Probability Distributions

Continuous Probability Distributions

Sampling Distributions and Estimation

One-Sample Hypothesis Tests

Two-Sample Hypothesis Tests

Analysis of Variance

Simple Regression

Multiple Regression

Time Series Analysis

Chi-Square Tests

Nonparametric Tests

Quality Management

Filters

Exam 4: Descriptive Statistics

VenalCo Market Research surveyed 50 individuals who recently purchased a certain CD, revealing the age distribution shown below. Which statement is least defensible?

Which is true of skewness?

The sum of the deviations around the mean is always zero.

The following frequency distribution shows the amount earned yesterday by employees of a large Las Vegas casino. Estimate the mean daily earnings. Earnings (dollars) Frequency 50<75 10 75<100 15 100<125 60 125<150 40 150<175 10

The midrange is not greatly affected by outliers.

Five homes were recently sold in Oxnard Acres. Four of the homes sold for $400,000, while the fifth home sold for $2.5 million. Which measure of central tendency best represents a typical home price in Oxnard Acres?

A trimmed mean may be preferable to a mean when a data set has extreme values.

John scored 85 on Prof. Hardtack's exam (Q1 = 40 and Q3 = 60). Based on the fences, which is correct?

A survey of 10 randomly chosen drivers showed the following number of persons per car, including the driver: 1, 5, 1, 5, 2, 1, 1, 1, 2, 1. Describe the center, variability, and skewness for this sample.

A positive kurtosis coefficient in Excel indicates a leptokurtic condition in a distribution.

A platykurtic distribution is more sharply peaked (i.e., thinner tails) than a normal distribution.

A population consists of the following data: 7, 11, 12, 18, 20, 22, 25. The population variance is:

If Q1 = 150 and Q3 = 250, the upper fences (inner and outer) are:

In calculating the sample variance, the sum of the squared deviations around the mean is divided by n - 1 to avoid underestimating the unknown population variance.

One disadvantage of the range is that:

If the standard deviations of two samples are the same, so are their coefficients of variation.C.V.

If there are 20 data values, the median will be halfway between two data values.

Overview of Statistics

Data Collection

Describing Data Visually

Probability

Discrete Probability Distributions

Continuous Probability Distributions

Sampling Distributions and Estimation

One-Sample Hypothesis Tests

Two-Sample Hypothesis Tests

Analysis of Variance

Simple Regression

Multiple Regression

Time Series Analysis

Chi-Square Tests

Nonparametric Tests

Quality Management

Filters

John scored 85 on Prof. Hardtack's exam (Q₁ = 40 and Q₃ = 60). Based on the fences, which is correct?

If Q₁ = 150 and Q₃ = 250, the upper fences (inner and outer) are: