Question 1

Find the mean for the given sample data. Unless otherwise specified, round your answer to one more decimal place thanthat used for the observations.
-Bill kept track of the number of hours he spent exercising each week. The results for four months are shown below. Find the mean number of hours Bill spent exercising per week. 
$\begin{array} { l l l l l l } 
8.1 & 8.6 & 8.7 & 7.5 & 8.3 & 8.1 \
8.7 & 8.7 & 7.9 & 8.1 & 7.5 & 6.6 \
7.3 & 8.6 & 8.6 & 8.6 & 8.3 & 8.7
\end{array}$

Accepted Answer

A) 7.73 hr 
B) 8.39 hr 
C) 8.64 hr 
D) 8.16 hr

Question 2

Find the sample standard deviation for the given data. Round your final answer to one more decimal place than that usedfor the observations.
-2, 6, 15, 9, 11, 22, 1, 4, 8, 19

Accepted Answer

A) 2.1 
B) 6.3 
C) 7.1 
D) 6.8

Question 3

Provide an appropriate response.
-A company's raw-data sample of weekly salaries (in dollars)is shown below. 
$\begin{array} { r r r r r r } 280 & 320 & 590 & 320 & 730 & 590 \ 320 & 590 & 280 & 320 & 1150 & 280 \end{array}$
A frequency distribution of this data set, based on single-value grouping, is presented below, with a third column showing the xf-values--the class midpoint (which here is the same as the class) times the class frequency.
$\begin{array}{|l|l|l|}
\hline \begin{array}{l}
\text { Salary } \
x
\end{array} & \begin{array}{l}
\text { Frequency } \
\text { f }
\end{array} & \begin{array}{l}
\text { Salary }{ }^{*} \text { Frequency } \
x f
\end{array} \
\hline 280 & 3 & 840 \
320 & 4 & 1280 \
590 & 3 & 1770 \
730 & 1 & 730 \
1150 & 1 & 1150 \
\hline
\end{array}$

Accepted Answer

A) (i)Use the raw data to obtain the sample standard deviation of the ungrouped data. Round your answer to two decimal places.
(ii)Use the grouped-data formula to obtain the sample standard deviation of the grouped data in
The frequency distribution. Round your answer to two decimal places.
(iii)Compare your answers in parts (i)and (ii). (i)The sample standard deviation of the ungrouped data is 264.59; (ii)The sample standard deviation of the grouped data is 264.59;
(iii)The results in parts (i)and (ii)are the same. The grouped data formula will always Provide the actual standard deviation when the data are grouped in classes each based on a Single value because the class midpoint is the same as each observation in each class. 
B) (i)The sample standard deviation of the ungrouped data is 286.28; (ii)The sample standard deviation of the grouped data is 286.28;
(iii)The results in parts (i)and (ii)are the same. The grouped data formula will always Provide the actual standard deviation when the data are grouped in classes each based on a Single value because the class midpoint is the same as each observation in each class. 
C) (i)The sample standard deviation of the ungrouped data is 264.59; (ii)The sample standard deviation of the grouped data is 286.28;
(iii)The results in parts (i)and (ii)are different. This discrepancy occurs because in the Grouped data formulas, every actual data value in a given class is replaced by the class Midpoint even though most values in the class are not equal to the midpoint. 
D) (i)The sample standard deviation of the ungrouped data is 286.28; (ii)The sample standard deviation of the grouped data is 299.01;
(iii)The results in parts (i)and (ii)are different. This discrepancy occurs because in the Grouped data formulas, every actual data value in a given class is replaced by the class Midpoint even though most values in the class are not equal to the midpoint.

Question 4

Determine the quartile or interquartile range as specified.
-The test scores of 19 students are listed below. Find the interquartile range. $\begin{array} { l l l l l } 91 & 47 & 86 & 69 & 61 \end{array}$
$\begin{array} { l l l l l } 63 & 97 & 57 & 90 & 76 \end{array}$
$\begin{array} { l l l l l } 82 & 83 & 53 & 88 & 75 \end{array}$
$\begin{array} { l l l l } 42 & 92 & 94 & 65 \end{array}$

Accepted Answer

A) 29 
B)  29.5 
C)  27 
D)  28.5

Question 5

Solve the problem.
-Here are boxplots of the points scored during the first 10 games of the basketball season for both Caroline and Alexandra. Summarize the similarities and differences in their performance so far.

Accepted Answer

A) The girls have a different average score per game. Caroline is much more consistent, because her IQR is about 4 points, while Alexandra's is over 15. In other words, Alexandra has more
Variation in her scores than does Caroline. The distribution of scores for Caroline is
Symmetric, while the distribution of scores for Alexandra is left-skewed. 
B) Both girls have a median score of about 18 points per game. Alexandra is much more consistent, because her IQR is about 15 points, while Caroline's is over 3. In other words,
Alexandra has less variation in her scores than does Caroline. The distribution of scores for
Both women is symmetric. 
C) Both girls have a median score of about 18 points per game. Caroline is much more consistent, because her IQR is about 6 points, while Alexandra's is over 20. In other words, Alexandra
Has more variation in her scores than does Caroline. The distribution of scores for Caroline is
Right skewed, while the distribution of scores for Alexandra is bell-shaped. 
D) Both girls have a median score of about 18 points per game. Caroline is much more consistent, because her IQR is about 4 points, while Alexandra's is over 15. In other words, Alexandra
Has more variation in her scores than does Caroline. The distribution of scores for both
Women is symmetric.

Question 6

Identify potential outliers, if any, for the given data.
-The ages of the 21 members of a track and field team are listed below. $$\begin{array} { l l l l l l l } 
15 & 18 & 18 & 19 & 22 & 23 & 24 \
24 & 24 & 24 & 25 & 26 & 26 & 27 \
28 & 28 & 30 & 32 & 33 & 40 & 42
\end{array}$$

Accepted Answer

A) 42 
B) 40, 42 
C) 15, 42 
D) None

Question 7

Find the range for the given data set.
-The test scores of 19 students are listed below. 
$\begin{array} { l l l l l } 91 & 99 & 86 & 54 & 72 \ 85 & 97 & 91 & 90 & 66 \ 82 & 83 & 78 & 88 & 77 \ 80 & 92 & 94 & 98 & \end{array}$

Accepted Answer

A) 54 
B)  45 
C)  44 
D)  33

Question 8

Find the sample standard deviation for the given data. Round your final answer to one more decimal place than that usedfor the observations.
-22, 29, 21, 24, 27, 28, 25, 36

Accepted Answer

A) 4.8 
B) 4.2 
C) 2.8 
D) 1.6

Question 9

Provide an appropriate response.
-Obtain the population standard deviation, Ϭ, for the given data. Assume that the data represent population data. Round your final answer to one more decimal place than that used for the
Observations.
The number of years of teaching experience is given below for 12 high-school teachers. 
$\begin{array} { r r r r r r } 4 & 22 & 22 & 12 & 12 & 19 \ 17 & 8 & 5 & 13 & 22 & 31 \end{array}$

Accepted Answer

A) $59.2 \mathrm { yr }$ 
B)  $7.7 \mathrm { yr }$ 
C)  $8.0 \mathrm { yr }$ 
D)  $9.3 \mathrm { yr }$

Question 10

Provide an appropriate response.
-Obtain the population standard deviation, Ϭ, for the given data. Assume that the data represent population data. Round your final answer to one more decimal place than that used for the
Observations. The weekly salaries (in dollars)of seven government workers are listed below $\begin{array} { l l l l l l l } 847 & 512 & 707 & 535 & 564 & 758 & 902 \end{array}$

Accepted Answer

A) $\$ 144.5$ 
B)  $\$ 20,868.8$ 
C)  $\$ 985.4$ 
D)  $\$ 156.0$

Question 11

The two most frequently used measures of central tendency are the mean and the median. Compare these two measures for the following characteristics: Takes every score into account? Affected by extreme scores? Advantages.

Accepted Answer

The answer of The two most frequently used measures of...

Question 12

A company had 80 employees whose salaries are summarized in the frequency distribution below. Find the standard deviation. $\begin{array}{c|c}
\text { Salary } & \text { Employees } \
\hline 5,000 \text {-under } 10,000 & 10 \
10,000 \text {-under } 15,000 & 17 \
15,000 \text {-under } 20,000 & 10 \
20,000 \text {-under } 25,000 & 19 \
25,000 \text {-under } 30,000 & 24
\end{array}$

Accepted Answer

A) $7702.9$ 
B)  $7916.9$ 
C)  $7132.3$ 
D)  $7489.0$

Question 13

In the Florida lottery, the numbers (between 1 and 49)are generated randomly with the expectation that each number has an equal chance of winning. Draw a boxplot which should illustrate the data set of all numbers picked for the lottery during the past year.

Accepted Answer

The answer of In the Florida lottery, the numbers (between...

Question 14

Does the mode of a data set always lie near the center? Explain your answer and give an example of a data set to illustrate your answer.

Accepted Answer

The answer of Does the mode of a data set...

Question 15

Find the median for the given sample data.
-1, 3, 10, 21, 30, 30, 49

Accepted Answer

A) 30 
B) 21 
C) 25.5 
D) 10

Question 16

To get the best deal on a CD player, Tom called eight appliance stores and asked the cost of a specific model. The prices he was quoted are listed below: $\begin{array} { l l l l l l l l } \$ 410 & \$ 377 & \$ 395 & \$ 114 & \$ 293 & \$ 169 & \$ 140 & \$ 224 \end{array}$

Accepted Answer

A) $\$ 663,436.0$ 
B)  $\$ 562,860.5$ 
C)  $\$119.9$ 
D)  $\$ 258.5$

Question 17

Obtain the five-number summary for the given data.
-The weights (in pounds)of 18 randomly selected adults are given below. $\begin{array} { l l l l l l } 120 & 146 & 187 & 155 & 119 & 138 \end{array}$
$\begin{array} { l l l l l l } 127 & 140 & 179 & 164 & 182 & 202 \end{array}$
$\begin{array} { l l l l l l } 114 & 173 & 133 & 150 & 169 & 173 \end{array}$

Accepted Answer

A) $114,133,152.5,173,202$ pounds 
B)  $114,131.50,150,174.50,202$ pounds 
C)  $114,130.00,150,171.0,202$ pounds 
D)  $114,130.00,230.5,171.0,202$ pounds

Question 18

Identify potential outliers, if any, for the given data.
-The weekly salaries (in dollars)of 24 randomly selected employees of a company are shown below. 
$\begin{array} { r r r r r r r r } 310 & 320 & 450 & 460 & 470 & 500 & 520 & 540 \ 580 & 600 & 650 & 700 & 710 & 840 & 870 & 900 \ 1000 & 1200 & 1250 & 1300 & 1400 & 1720 & 2500 & 3700 \end{array}$

Accepted Answer

A) $310,2500,3700$ 
B)  3700 
C)  2500,3700 
D)  2500

Question 19

Find the range for the given data set.
-Here are costs (in dollars)of 12 electric smoothtop ranges. $\begin{array} { l l l l l l } 845 & 970 & 635 & 545 & 1445 & 1070 \end{array}$
$\begin{array} { l l l l l l } 670 & 745 & 780 & 1270 & 535 & 1045 \end{array}$

Accepted Answer

A) $\$ 950$ 
B)  $\$ 910$ 
C)  $\$ 890$ 
D)  $\$ 930$

Question 20

Suppose that a state introduces a state income tax which will be at a flat rate of 3%. The state legislature wishes to estimate how much money they will receive in taxes, and to do this they need to know the average income of residents of the state. Which information would be most useful, the mean income, the median income, or the mode of the incomes? Why?

Accepted Answer

The answer of Suppose that a state introduces a state...

Exam 3: Descriptive Measures

Find the sample standard deviation for the given data. Round your final answer to one more decimal place than that usedfor the observations. -2, 6, 15, 9, 11, 22, 1, 4, 8, 19

Solve the problem. -Here are boxplots of the points scored during the first 10 games of the basketball season for both Caroline and Alexandra. Summarize the similarities and differences in their performance so far.

Identify potential outliers, if any, for the given data. -The ages of the 21 members of a track and field team are listed below. $\begin{array} { l l l l l l l } 15 & 18 & 18 & 19 & 22 & 23 & 24 \\24 & 24 & 24 & 25 & 26 & 26 & 27 \\28 & 28 & 30 & 32 & 33 & 40 & 42\end{array}$

Find the range for the given data set. -The test scores of 19 students are listed below. $\begin{array} { l l l l l } 91 & 99 & 86 & 54 & 72 \\ 85 & 97 & 91 & 90 & 66 \\ 82 & 83 & 78 & 88 & 77 \\ 80 & 92 & 94 & 98 & \end{array}$

Find the sample standard deviation for the given data. Round your final answer to one more decimal place than that usedfor the observations. -22, 29, 21, 24, 27, 28, 25, 36

The two most frequently used measures of central tendency are the mean and the median. Compare these two measures for the following characteristics: Takes every score into account? Affected by extreme scores? Advantages.

In the Florida lottery, the numbers (between 1 and 49)are generated randomly with the expectation that each number has an equal chance of winning. Draw a boxplot which should illustrate the data set of all numbers picked for the lottery during the past year.

Does the mode of a data set always lie near the center? Explain your answer and give an example of a data set to illustrate your answer.

Find the median for the given sample data. -1, 3, 10, 21, 30, 30, 49

To get the best deal on a CD player, Tom called eight appliance stores and asked the cost of a specific model. The prices he was quoted are listed below: $\begin{array} { l l l l l l l l } \$ 410 & \$ 377 & \$ 395 & \$ 114 & \$ 293 & \$ 169 & \$ 140 & \$ 224 \end{array}$

Find the range for the given data set. -Here are costs (in dollars) of 12 electric smoothtop ranges. $\begin{array} { l l l l l l } 845 & 970 & 635 & 545 & 1445 & 1070 \end{array}$ $\begin{array} { l l l l l l } 670 & 745 & 780 & 1270 & 535 & 1045 \end{array}$