Question 1

Andrew Costanzo has a stock portfolio that contains 24 shares of stock A and six shares of stock B.Over the past year, the value of a share of stock A went up to $3.00 and the value of a share of stock B fell to $50.Apply a weighted average approach to produce the current average value per share in Andrew's portfolio.

Accepted Answer

A) 15.7 
B) 12.4 
C) 13.8 
D) 21.3 
E) 14.9

Question 2

A __________ makes use of the five number summary.

Accepted Answer

A) box plot 
B) stem-and-leaf diagram 
C) a scatter diagram 
D) a bar chart 
E) a histogram

Question 3

A particular data set follows the bell-shaped pattern of a normal distribution, with a mean of 3.5 minutes and a standard deviation of 1.1 minutes.What proportion of service times will be between 3.5 and 4.6 minutes?

Accepted Answer

A) about .819 
B) about .764 
C) about .665 
D) about .77.6 
E) about .697

Question 4

Peak efficiency levels (in %) for the wind turbines at Miner's Point are shown for a sample of 10 days in April.According to the "1.5 x interquartile range" approach to identifying outliers, determine the outlier(s), if any, here.

Accepted Answer

A) 69 and 80.5 
B) 69 
C) 74.9 and 80.5 
D) 80.5 
E) There are no outliers

Question 5

Which of the following statements is NOT true regarding the z-score?

Accepted Answer

A) it can be calculated as the data value minus the mean divided by the variance 
B) it is a standardized value (has no units) 
C) it denotes the number of standard deviations a data value is from the mean 
D) a data value less than the mean will have a z-score less than zero 
E) a data value with a z-score less than -3 or greater than +3 might be considered an outlier

Question 6

Compared to the range, the interquartile range:

Accepted Answer

A) is less affected by extreme values. 
B) is more affected by extreme values. 
C) is likely to be closer to the value of the mean. 
D) is likely to be closer to the value of the median. 
E) is likely to be closer to the value of the mode.

Question 7

The data below show the GDP per capita in dollars of the 28 member countries of the European Union.  Create a stem-and-leaf diagram to display the data using two leading digits to form the stem.Use a "leaf unit" of 100 so that you can construct the diagram using only one-digit leaves.Retain the original order, reading first down the column, when entering the leaf values.In your diagram, the row in which "2" and "7" are the 2 leading digits should look like:

Accepted Answer

A) 27 l 0 8 6 
B) 27 l 0 1 0 
C) 27 l 1 2 0 
D) 27 l 0 2 2 
E) 27 l 0 2 4

Question 8

The data below show the average number of orders shipped daily (x) during the past 8 months and the average value of each order (y).Use the coefficient of variation to compare the degree of variation in each of the two data sets and use the result to identify which data set shows the greater degree of variation.

Accepted Answer

A) With a Coefficient of Variation equal to .032 (or 3.2%), x shows the greater variation. 
B) With a Coefficient of Variation equal to .036 (or 3.6%), y shows the greater variation. 
C) With a Coefficient of Variation equal to .092 (or 9.2%), y shows the greater variation. 
D) With a Coefficient of Variation equal to .046 (or 4.6%), y shows the greater variation. 
E) With a Coefficient of Variation equal to .058 (or 5.8%), x shows the greater variation.

Question 9

In a recent survey, 18 college freshmen were asked how many text messages they had send or received on the day of the survey.Results are shown below.Determine the 85th percentile value. 45, 256, 23, 110, 168, 122, 135, 56, 18, 0, 44, 68, 120, 115, 456, 256, 174, 88

Accepted Answer

A) 250 
B) 270.5 
C) 174 
D) 256 
E) 210.5

Question 10

The data below show the GDP per capita in dollars of the 28 member countries of the European Union.According to the "1.5 x interquartile range" approach to identifying outliers, determine the outlier(s), if any, here.

Accepted Answer

A) 12,808 
B) 12,808 and 14,312 
C) 79,785 
D) 12,808 and 79,785 
E) 12,808, 14,312, and 79,785

Question 11

A __________ visually shows the relationship between two quantitative variables.

Accepted Answer

A) box plot 
B) stem-and-leaf diagram 
C) a scatter diagram 
D) a bar chart 
E) a histogram

Question 12

The five number summary is used to produce which of the following graphical charts, diagrams, or plots:

Accepted Answer

A) a pie chart 
B) a histogram 
C) a stem-and-leaf diagram 
D) a box plot 
E) a scatter diagram

Question 13

An outlier is a data value that has a z-score less than -1.5 or is greater than Q3-1.5*IQR.

Accepted Answer

A) True 
 B)False

Question 14

The table shows life expectancy in years of the G8 countries (Datablog, Guardian.co.uk, July 8 2009).Treating the data as a population, calculate the z-score for life expectancy in Russia.

Accepted Answer

A) -12.00 
B) -2.26 
C) -2.11 
D) 3.42 
E) 5.32

Question 15

The geometric mean is appropriate any time the values being averaged are of unequal importance.

Accepted Answer

A) True 
 B)False

Question 16

The population of Ecuador rose from 9.9 million in 1996 to 15.0 million in 2013.Using the geometric mean, compute the average annual rate of increase over this 17-year period.

Accepted Answer

A) 3.16% 
B) 5.09% 
C) 1.56% 
D) 2.77% 
E) 2.47%

Question 17

Peak efficiency levels (in %) for the wind turbines at Miner's Point are shown for a sample of 10 days in April.According to the ""three-standard-deviation" approach to identifying outliers, determine the outlier(s), if any, here.

Accepted Answer

A) 69 and 80.5 
B) 69 
C) 74.9 and 80.5 
D) 80.5 
E) There are no outliers

Question 18

In a test of RiteAid.com's new website, search times for 20 trial orders were recorded, in minutes.Results are reported in the table:  Construct a proper stem-and-leaf diagram for the data.One of the rows in the table would look like:

Accepted Answer

A) 1 l 2 6 4 4 9 3 
B) 2 l 2 4 5 4 2 4 6 
C) 3 l 5 6 2 7 
D) 2 l 2 4 6 4 3 5 6 
E) 2 l 2 4 5 6 3 5 6

Question 19

In a test of RiteAid.com's new website, search times for 20 trial orders were recorded, in minutes.Results are reported in the table:  Construct an ORDERED stem-and-leaf diagram for the data.One of the rows in the table would look like:

Accepted Answer

A) 1 l 2 4 4 5 6 9 
B) 3 l 2 5 6 8 
C) 1 l 2 3 4 4 8 9 
D) 2 l 2 3 4 4 5 6 
E) 2 l 2 3 4 4 5 7

Question 20

In a recent survey, 18 college freshmen were asked how many text messages they had send or received on the day of the survey.Results are shown below.Determine the median value. 45, 256, 23, 110, 168, 122, 135, 56, 18, 0, 44, 68, 120, 115, 456, 256, 174, 88

Accepted Answer

A) 110 
B) 106.5 
C) 120 
D) 115.5 
E) 112.5

Exam 3: Descriptive Statistics II: Additional Descriptive Measures and Data Displays

A __________ makes use of the five number summary.

A particular data set follows the bell-shaped pattern of a normal distribution, with a mean of 3.5 minutes and a standard deviation of 1.1 minutes.What proportion of service times will be between 3.5 and 4.6 minutes?

Peak efficiency levels (in %) for the wind turbines at Miner's Point are shown for a sample of 10 days in April.According to the "1.5 x interquartile range" approach to identifying outliers, determine the outlier(s) , if any, here.

Which of the following statements is NOT true regarding the z-score?

Compared to the range, the interquartile range:

In a recent survey, 18 college freshmen were asked how many text messages they had send or received on the day of the survey.Results are shown below.Determine the 85th percentile value. 45, 256, 23, 110, 168, 122, 135, 56, 18, 0, 44, 68, 120, 115, 456, 256, 174, 88

The data below show the GDP per capita in dollars of the 28 member countries of the European Union.According to the "1.5 x interquartile range" approach to identifying outliers, determine the outlier(s) , if any, here.

A __________ visually shows the relationship between two quantitative variables.

The five number summary is used to produce which of the following graphical charts, diagrams, or plots:

An outlier is a data value that has a z-score less than -1.5 or is greater than Q3-1.5*IQR.

The table shows life expectancy in years of the G8 countries (Datablog, Guardian.co.uk, July 8 2009) .Treating the data as a population, calculate the z-score for life expectancy in Russia.

The geometric mean is appropriate any time the values being averaged are of unequal importance.

The population of Ecuador rose from 9.9 million in 1996 to 15.0 million in 2013.Using the geometric mean, compute the average annual rate of increase over this 17-year period.

Peak efficiency levels (in %) for the wind turbines at Miner's Point are shown for a sample of 10 days in April.According to the ""three-standard-deviation" approach to identifying outliers, determine the outlier(s) , if any, here.

In a test of RiteAid.com's new website, search times for 20 trial orders were recorded, in minutes.Results are reported in the table: Construct a proper stem-and-leaf diagram for the data.One of the rows in the table would look like:

In a test of RiteAid.com's new website, search times for 20 trial orders were recorded, in minutes.Results are reported in the table: Construct an ORDERED stem-and-leaf diagram for the data.One of the rows in the table would look like:

In a recent survey, 18 college freshmen were asked how many text messages they had send or received on the day of the survey.Results are shown below.Determine the median value. 45, 256, 23, 110, 168, 122, 135, 56, 18, 0, 44, 68, 120, 115, 456, 256, 174, 88