Question 1

The 25th percentile for waiting time in a doctor's office is 10 minutes.The 75th percentile is 30 minutes.Which is incorrect regarding the fences?

Accepted Answer

A) The upper inner fence is 60 minutes. 
B) The upper outer fence is 90 minutes. 
C) A waiting time of 45 minutes would be an outlier. 
D) The lower fences are not relevant in this problem. 
A) The upper inner fence is 60 minutes. 
B) The upper outer fence is 90 minutes. 
C) A waiting time of 45 minutes would be an outlier. 
D) The lower fences are not relevant in this problem.

Question 2

Bob's sample of freshman GPAs showed a mean of 2.72 with a standard deviation of 0.31.(a)What range would you predict for all the grades? For the middle 95 percent? Explain.(b)Why might your estimates be inaccurate?

Accepted Answer

By the Empirical Rule,we expect the midd

Question 3

The quartiles of a distribution are most clearly revealed in which display?

Accepted Answer

A) Box plot 
B) Scatter plot 
C) Histogram 
D) Dot plot 
A) Box plot 
B) Scatter plot 
C) Histogram 
D) Dot plot

Question 4

The following table is the frequency distribution of parking fees for a day:   What is the mean parking fee?

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 5

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 6

Twelve randomly chosen students were asked how many times they had missed class during a certain semester,with this result: 2,1,5,1,1,3,4,3,1,1,5,18.For this sample,the geometric mean is

Accepted Answer

A) 2.158 
B) 1.545 
C) 2.376 
D) 3.017 
A) 2.158 
B) 1.545 
C) 2.376 
D) 3.017

Question 7

Which of the following statements is likely to be true?

Accepted Answer

A) The median personal income of California taxpayers would probably be near the mean. 
B) The interquartile range offers a measure of income inequality among California residents. 
C) For income,the sum of squared deviations about the mean is negative about half the time. 
D) For personal incomes in California,outliers in either tail would be equally likely. 
A) The median personal income of California taxpayers would probably be near the mean. 
B) The interquartile range offers a measure of income inequality among California residents. 
C) For income,the sum of squared deviations about the mean is negative about half the time. 
D) For personal incomes in California,outliers in either tail would be equally likely.

Question 8

Based on daily measurements,Bob's weight has a mean of 200 pounds with a standard deviation of 16 pounds,while Mary's weight has a mean of 125 pounds with a standard deviation of 15 pounds.Who has the smaller relative variation?

Accepted Answer

A) Bob 
B) Mary 
C) They are the same. 
A) Bob 
B) Mary 
C) They are the same.

Question 9

When applying the Empirical Rule to a distribution of grades,if a student scored one standard deviation below the mean,then she would be at the 25th percentile of the distribution.

Accepted Answer

A) True 
 B)False

Question 10

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.

Question 11

When data are right-skewed,we expect the median to be greater than the mean.

Accepted Answer

A) True 
 B)False

Question 12

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 13

So far this year,stock A has had a mean price of $6.58 per share with a standard deviation of $1.88,while stock B has had a mean price of $10.57 per share with a standard deviation of $3.02.Which stock is more volatile?

Accepted Answer

A) Stock A 
B) Stock B 
C) They are the same. 
A) Stock A 
B) Stock B 
C) They are the same.

Question 14

If there are 19 data values,the median will have 10 values above it and 9 below it since n is odd.

Accepted Answer

A) True 
 B)False

Question 15

Ten randomly chosen students at a certain university were asked how many times they smoked marijuana during the preceding week.Their answers were 0,8,0,0,2,4,0,0,6,0.A campus newspaper article appeared,with the headline "Average Student Uses No Pot." Is this a fair assessment of central tendency? Discuss the alternatives.

Accepted Answer

Mode and median are 0,but the mean is 2.

Question 16

If the mean and median of a population are the same,then its distribution is

Accepted Answer

A) normal. 
B) skewed. 
C) symmetric. 
D) uniform. 
A) normal. 
B) skewed. 
C) symmetric. 
D) uniform.

Question 17

Find the standard deviation of this sample: 4,7,9,12,15.

Accepted Answer

A) 4.550 
B) 3.798 
C) 4.278 
D) 2.997 
A) 4.550 
B) 3.798 
C) 4.278 
D) 2.997

Question 18

The sum of the deviations around the mean is

Accepted Answer

A) greater than zero if data are right-skewed. 
B) smaller when the units are smaller (e.g. ,milligrams versus kilograms). 
C) always zero. 
D) dependent on the sample size. 
A) greater than zero if data are right-skewed. 
B) smaller when the units are smaller (e.g. ,milligrams versus kilograms). 
C) always zero. 
D) dependent on the sample size.

Question 19

Which is not a measure of variability?

Accepted Answer

A) Mean absolute deviation (MA
D)  
B) Range 
C) Coefficient of variation 
D) Trimmed mean 
A) Mean absolute deviation (MA
D)  
B) Range 
C) Coefficient of variation 
D) Trimmed mean

Question 20

The following frequency distribution shows the amount earned yesterday by employees of a large Las Vegas casino.Estimate the mean daily earnings.

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

The 25th percentile for waiting time in a doctor's office is 10 minutes.The 75th percentile is 30 minutes.Which is incorrect regarding the fences?

Bob's sample of freshman GPAs showed a mean of 2.72 with a standard deviation of 0.31.(a)What range would you predict for all the grades? For the middle 95 percent? Explain.(b)Why might your estimates be inaccurate?

The quartiles of a distribution are most clearly revealed in which display?

The following table is the frequency distribution of parking fees for a day: What is the mean parking fee?

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?

Twelve randomly chosen students were asked how many times they had missed class during a certain semester,with this result: 2,1,5,1,1,3,4,3,1,1,5,18.For this sample,the geometric mean is

Which of the following statements is likely to be true?

Based on daily measurements,Bob's weight has a mean of 200 pounds with a standard deviation of 16 pounds,while Mary's weight has a mean of 125 pounds with a standard deviation of 15 pounds.Who has the smaller relative variation?

When applying the Empirical Rule to a distribution of grades,if a student scored one standard deviation below the mean,then she would be at the 25th percentile of the distribution.

When data are right-skewed,we expect the median to be greater than the mean.

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?

So far this year,stock A has had a mean price of $6.58 per share with a standard deviation of $1.88,while stock B has had a mean price of $10.57 per share with a standard deviation of $3.02.Which stock is more volatile?

If there are 19 data values,the median will have 10 values above it and 9 below it since n is odd.

If the mean and median of a population are the same,then its distribution is

Find the standard deviation of this sample: 4,7,9,12,15.

The sum of the deviations around the mean is

Which is not a measure of variability?

The following frequency distribution shows the amount earned yesterday by employees of a large Las Vegas casino.Estimate the mean daily earnings.

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

Chi-Square Tests

Filters

Exam 4: Descriptive Statistics

The 25th percentile for waiting time in a doctor's office is 10 minutes.The 75th percentile is 30 minutes.Which is incorrect regarding the fences?

Bob's sample of freshman GPAs showed a mean of 2.72 with a standard deviation of 0.31.(a)What range would you predict for all the grades? For the middle 95 percent? Explain.(b)Why might your estimates be inaccurate?

The quartiles of a distribution are most clearly revealed in which display?

The following table is the frequency distribution of parking fees for a day: What is the mean parking fee?

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?

Twelve randomly chosen students were asked how many times they had missed class during a certain semester,with this result: 2,1,5,1,1,3,4,3,1,1,5,18.For this sample,the geometric mean is

Which of the following statements is likely to be true?

Based on daily measurements,Bob's weight has a mean of 200 pounds with a standard deviation of 16 pounds,while Mary's weight has a mean of 125 pounds with a standard deviation of 15 pounds.Who has the smaller relative variation?

When applying the Empirical Rule to a distribution of grades,if a student scored one standard deviation below the mean,then she would be at the 25th percentile of the distribution.

When data are right-skewed,we expect the median to be greater than the mean.

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?

So far this year,stock A has had a mean price of $6.58 per share with a standard deviation of $1.88,while stock B has had a mean price of $10.57 per share with a standard deviation of $3.02.Which stock is more volatile?

If there are 19 data values,the median will have 10 values above it and 9 below it since n is odd.

If the mean and median of a population are the same,then its distribution is

Find the standard deviation of this sample: 4,7,9,12,15.

The sum of the deviations around the mean is

Which is not a measure of variability?

The following frequency distribution shows the amount earned yesterday by employees of a large Las Vegas casino.Estimate the mean daily earnings.

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

Chi-Square Tests

Filters