Question 1

Which statement is true?

Accepted Answer

A) With nominal data we can find the mode. 
B) Outliers distort the mean but not the standard deviation. 
C) Business and economic data are rarely skewed to the right. 
D) If we sample a normal population, the sample skewness coefficient is exactly 0. 
A) With nominal data we can find the mode. 
B) Outliers distort the mean but not the standard deviation. 
C) Business and economic data are rarely skewed to the right. 
D) If we sample a normal population, the sample skewness coefficient is exactly 0.

Question 2

Which is true of the kurtosis of a distribution?

Accepted Answer

A) A distribution that is flatter than a normal distribution (i.e., thicker tails) is mesokurtic. 
B) A distribution that is more peaked than a normal distribution (i.e., thinner tails) is platykurtic. 
C) It is risky to assess kurtosis if the sample size is less than 50. 
D) The expected range of the kurtosis coefficient increases as n increases. 
A) A distribution that is flatter than a normal distribution (i.e., thicker tails) is mesokurtic. 
B) A distribution that is more peaked than a normal distribution (i.e., thinner tails) is platykurtic. 
C) It is risky to assess kurtosis if the sample size is less than 50. 
D) The expected range of the kurtosis coefficient increases as n increases.

Question 3

Exam scores in a small class were 10, 10, 20, 20, 40, 60, 80, 80, 90, 100, 100. For this data set, which statement is incorrect concerning measures of center?

Accepted Answer

A) The median is 60.00. 
B) The mode is not helpful. 
C) The 5 percent trimmed mean would be awkward. 
D) The geometric mean is 35.05. 
A) The median is 60.00. 
B) The mode is not helpful. 
C) The 5 percent trimmed mean would be awkward. 
D) The geometric mean is 35.05.

Question 4

A 10-point quiz was given by Professor Ennuyeaux. Of the 10 students in the class, half got zero and the others got perfect scores. List the students' scores. Then find the mean, median, mode, and geometric mean of their scores. Which is the most appropriate measure of center? The least appropriate?

Accepted Answer

Mean is 5, median is

Question 5

The 25th percentile for waiting time in a doctor's office is 19 minutes. The 75th percentile is 31 minutes. Which is incorrect regarding the fences?

Accepted Answer

A) The upper inner fence is 49 minutes. 
B) The upper outer fence is 67 minutes. 
C) A waiting time of 45 minutes exceeds the upper inner fence. 
D) A waiting time of 70 minutes would be an outlier. 
A) The upper inner fence is 49 minutes. 
B) The upper outer fence is 67 minutes. 
C) A waiting time of 45 minutes exceeds the upper inner fence. 
D) A waiting time of 70 minutes would be an outlier.

Question 6

Which is not a characteristic of the standard deviation?

Accepted Answer

A) It is always the square root of the variance. 
B) It is not applicable when data are continuous. 
C) It can be calculated when the data contain negative or zero values. 
D) Its physical interpretation is not as easy as the MAD. 
A) It is always the square root of the variance. 
B) It is not applicable when data are continuous. 
C) It can be calculated when the data contain negative or zero values. 
D) Its physical interpretation is not as easy as the MAD.

Question 7

When using Chebyshev's Theorem, the minimum percentage of sample observations that will fall within two standard deviations of the mean will be __________ the percentage within two standard deviations if a normal distribution is assumed (Empirical Rule).

Accepted Answer

A) smaller than 
B) greater than 
C) the same as 
A) smaller than 
B) greater than 
C) the same as

Question 8

As a measure of variability, compared to the range, an advantage of the standard deviation is:

Accepted Answer

A) being calculated easily through the use of a formula. 
B) considering only the data values in the middle of the data array. 
C) describing the distance between the highest and lowest values. 
D) considering all data values. 
A) being calculated easily through the use of a formula. 
B) considering only the data values in the middle of the data array. 
C) describing the distance between the highest and lowest values. 
D) considering all data values.

Question 9

The following table is the frequency distribution of parking fees for a day: $$\begin{array} { l c } 
\text { Fee (dollars) } & \text { Number of Garages } \
6.00 < 6.50 & 5 \
6.50 < 7.00 & 8 \
7.00 < 7.50 & 10 \
7.50 < 8.00 & 7
\end{array}$$ The mean parking fee is:

Accepted Answer

A) $7.07. 
B) $6.95. 
C) $7.00. 
D) $7.25. 
A) $7.07. 
B) $6.95. 
C) $7.00. 
D) $7.25.

Question 10

Here are advertised prices of 21 used Chevy Blazers. Describe the distribution (center, variability, shape).

Accepted Answer

Range is from 7,000 to almost

Which statement is true?

Which is true of the kurtosis of a distribution?

Exam scores in a small class were 10, 10, 20, 20, 40, 60, 80, 80, 90, 100, 100. For this data set, which statement is incorrect concerning measures of center?

A 10-point quiz was given by Professor Ennuyeaux. Of the 10 students in the class, half got zero and the others got perfect scores. List the students' scores. Then find the mean, median, mode, and geometric mean of their scores. Which is the most appropriate measure of center? The least appropriate?

The 25^th percentile for waiting time in a doctor's office is 19 minutes. The 75^th percentile is 31 minutes. Which is incorrect regarding the fences?

Which is not a characteristic of the standard deviation?

When using Chebyshev's Theorem, the minimum percentage of sample observations that will fall within two standard deviations of the mean will be __________ the percentage within two standard deviations if a normal distribution is assumed (Empirical Rule).

As a measure of variability, compared to the range, an advantage of the standard deviation is:

The following table is the frequency distribution of parking fees for a day: Fee (dollars) Number of Garages 6.00<6.50 5 6.50<7.00 8 7.00<7.50 10 7.50<8.00 7 The mean parking fee is:

Here are advertised prices of 21 used Chevy Blazers. Describe the distribution (center, variability, shape).

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

Which statement is true?

Which is true of the kurtosis of a distribution?

Exam scores in a small class were 10, 10, 20, 20, 40, 60, 80, 80, 90, 100, 100. For this data set, which statement is incorrect concerning measures of center?

The 25th percentile for waiting time in a doctor's office is 19 minutes. The 75th percentile is 31 minutes. Which is incorrect regarding the fences?

Which is not a characteristic of the standard deviation?

When using Chebyshev's Theorem, the minimum percentage of sample observations that will fall within two standard deviations of the mean will be __________ the percentage within two standard deviations if a normal distribution is assumed (Empirical Rule).

As a measure of variability, compared to the range, an advantage of the standard deviation is:

The following table is the frequency distribution of parking fees for a day: Fee (dollars) Number of Garages 6.00<6.50 5 6.50<7.00 8 7.00<7.50 10 7.50<8.00 7 The mean parking fee is:

Here are advertised prices of 21 used Chevy Blazers. Describe the distribution (center, variability, shape).

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

The 25^th percentile for waiting time in a doctor's office is 19 minutes. The 75^th percentile is 31 minutes. Which is incorrect regarding the fences?