Question 1

Approximately what percentage of apple diameters is greater than the 66th percentile?

Accepted Answer

A)   66%
B)   17%
C)   34%
D)   3.4% C

Question 2

Listed below are the arrival delay times (in minutes)of randomly selected flights between New
York's JFK airport to Los Angeles (LAX). Negative values correspond to flights that arrive
before their schedule time and positive values represent delays. Calculate the range of the data
and the standard deviation. Can the standard deviation be negative? $$\begin{array} { l l l l l l l l } 
- 15 & - 18 & - 32 & - 21 & - 9 & - 32 & 11 & 2
\end{array}$$

Accepted Answer

The range is 43 min; s = 15.2 min. The standard deviation cannot be negative.

Question 3

The race speeds (in minutes)for the top eight cars in a 200-mile race are listed below. Use the range rule of thumb to estimate the standard deviation. Round results to the nearest tenth. $$\begin{array} { l l l l l l l l } 
181.0 & 180.6 & 189.2 & 182.2 & 175.6 & 180.0 & 177.9 & 181.8
\end{array}$$

Accepted Answer

A)   1.1 minutes
B)   6.8 minutes
C)   7.5 minutes
D)   3.4 minutes  D

Question 4

The mean height of a basketball team is 6 feet with a standard deviation of 0.2 feet. The team's center is 6.9 feet tall. Find the center's z score. Is his score unusual?

Accepted Answer

A)   4.95, yes
B)   4.5, yes
C)   3.83, no
D)   4, no

Question 5

The test scores of 40 students are listed below. Find P85
$\begin{array}{lllllllll}
30 & 35 & 43 & 44 & 47 & 48 & 54 & 55 & 56&57 \
59 & 62 & 63 & 65 & 66 & 68 & 69 & 69&71&72 \
72 & 73 & 74 & 76 & 77 & 77 & 78 & 79 & 80 &81\
81 & 82 & 83 & 85 & 89 & 92 & 93 & 94&97 & 98
\end{array}$

Accepted Answer

A)   87
B)   85
C)   89
D)   34

Question 6

A department store has daily mean sales of $ 28,372.72. The standard deviation of sales is $2000. On Tuesday, the store sold $34,885.21 worth of goods. Find Tuesday's z score. Was Tuesday a significantly good day?

Accepted Answer

A)   3.26, yes
B)   3.42, no
C)   2.61, no
D)   3.57, yes

Question 7

The owner of a manufacturing plant employs eighty people. As part of their personnel file, she asked each one to record to the nearest one-tenth of a mile the distance they travel one way
From home to work. The distances for a random sample of six employees are listed below: $$\begin{array} { l l l l l l } 
26 & 32 & 29 & 16 & 45 & 19
\end{array}$$ Find the variance for the given data.

Accepted Answer

A)   18.9 mi2
B)   5043.6 mi2
C)   15.8 mi2
D)   107.0 mi2

Question 8

A store manager kept track of the number of newspapers sold each week over a seven-week period. The results are shown below. $$\begin{array} { l l l l l l l } 
81 & 71 & 202 & 113 & 269 & 248 & 242
\end{array}$$ Find the median number of newspapers sold.

Accepted Answer

A)   202 newspapers
B)   113 newspapers
C)   175 newspapers
D)   242 newspapers

Question 9

Explain how two data sets could have equal means and modes but still differ greatly. Give
an example with two data sets to illustrate.

Accepted Answer

The answer of Explain how two data sets could have...

Question 10

When finding percentiles, if the locator L is not a whole number, one procedure is to interpolate so that a locator of 23.75, for example, leads to a value that is 3/4 of the way
Between the 23rd and 24th scores. Use this method of interpolation to find P75 for the set of
Test scores below.
 $\begin{array} { l l l l l l } 51 & 54 & 64 & 68 & 72 & 74 \end{array}$
$\begin{array} { l l l l l } 76 & 83 & 94 & 94 & 99 \end{array}$

Accepted Answer

A)   83
B)   88.5
C)   85.75
D)   94

Question 11

The mean of a set of data is 108.06 and its standard deviation is 115.45. Find the z score for a value of 489.67.

Accepted Answer

A)   2.98
B)   3.64
C)   3.31
D)   3.61

Question 12

A student earned grades of 84, 78, 84, and 72 on her four regular tests. She earned a grade of 78 on the final exam and 86 on her class projects. Her combined homework grade was 87. The Four regular tests count for 40% of the course grade, the final exam counts for 30%, the project Counts for 10%, and homework counts for 20%. What is her weighted mean grade? Round to
One decimal place.

Accepted Answer

A)   81.3
B)   80.2
C)   81.2
D)   82.1

Question 13

Use the following duration times (seconds)of 24 eruptions of the Old Faithful geyser in
Yellowstone National Park. The duration times are sorted from lowest to highest. $$\begin{array} { c c c c c c c c c c c c } 
110 & 120 & 178 & 213 & 234 & 234 & 235 & 237 & 240 & 243 & 245 & 245 \
250 & 250 & 251 & 252 & 254 & 255 & 255 & 259 & 260 & 266 & 269 & 273
\end{array}$$ Describe how to calculate the limits to determine outliers for this data set? Identify any
outliers.

Accepted Answer

The answer of Use the following duration times (seconds)of 24...

Question 14

In a data set with a range of 55.4 to 105.4 and 400 observations, there are 276 observations with values less than 86. Find the percentile for 86.

Accepted Answer

A)    P122.56P _ { 122.56 }P122.56​ 
B)    P32P _ { 32 }P32​ 
C)    P69P _ { 69 }P69​ 
D)    P612P _ { 612 }P612​

Question 15

Construct a data set for which the range is misleading as a measure of variation.
the range is misleading and suggest an alternative measure of variation.

Accepted Answer

The answer of Construct a data set for which the...

Question 16

Dave is a college student contemplating a possible career option. One factor that will
influence his decision is the amount of money he is likely to make. He decides to look up the
average salary of graduates in that profession. Which information would be more useful to
him, the mean salary or the median salary. Why?

Accepted Answer

The answer of Dave is a college student contemplating a...

Question 17

An engineer is designing a machine to manufacture gloves and she obtains the following
sample of hand lengths (mm)of randomly selected adult males based on data gathered: $$\begin{array} { l l l l l l l l } 
173 & 179 & 207 & 158 & 196 & 195 & 214 & 199
\end{array}$$ Define this data set as discrete or continuous. The hand lengths is what type of level of
measurement? Compare the mean and median for this data set and if you can draw any
conclusions from these values.

Accepted Answer

The answer of An engineer is designing a machine to...

Question 18

Jorge has his own business as a painter. The amounts he made in the last five months are shown below: $$\begin{array} { | l l l l l } 
\$ 2426 & \$ 2463 & \$ 1451 & \$ 2154 & \$ 1119
\end{array}$$ Find the mean, median, and range of the data.

Accepted Answer

A)   Mean = $1923, Median = $2154, Range = $1344
B)   Mean = $2154, Median = $1923, Range = $1344
C)   Mean = $1923, Median = $2154, Range = - $1344

Question 19

A test score of 48.4 on a test having a mean of 66 and a standard deviation of 11. Find the z score corresponding to the given value and use the z score to determine whether the value is
Significant. Consider a score to be significant if its z score is less than -2.00 or greater than 2.00. Round the z score to the nearest tenth if necessary.

Accepted Answer

A)   -17.6; significant
B)   -1.6; significant
C)   -1.6; not significant
D)   1.6; not significant

Question 20

The textbook defines significantly low or high values as those data points with z scores less
than z =−2.00 or z scores greater than z = 2.00. Comment on this definition with respect to
Chebyshev's theorem; refer specifically to the percent of scores which would be defined as
significant according to Chebyshev's theorem.

Accepted Answer

The answer of The textbook defines significantly low or high...

Exam 3: Describing, Exploring, and Comparing Data

Approximately what percentage of apple diameters is greater than the 66th percentile?

The race speeds (in minutes) for the top eight cars in a 200-mile race are listed below. Use the range rule of thumb to estimate the standard deviation. Round results to the nearest tenth. $\begin{array} { l l l l l l l l } 181.0 & 180.6 & 189.2 & 182.2 & 175.6 & 180.0 & 177.9 & 181.8\end{array}$

The mean height of a basketball team is 6 feet with a standard deviation of 0.2 feet. The team's center is 6.9 feet tall. Find the center's z score. Is his score unusual?

The test scores of 40 students are listed below. Find P85 $\begin{array}{lllllllll}30 & 35 & 43 & 44 & 47 & 48 & 54 & 55 & 56&57 \\59 & 62 & 63 & 65 & 66 & 68 & 69 & 69&71&72 \\72 & 73 & 74 & 76 & 77 & 77 & 78 & 79 & 80 &81\\81 & 82 & 83 & 85 & 89 & 92 & 93 & 94&97 & 98\end{array}$

A department store has daily mean sales of $ 28,372.72. The standard deviation of sales is $2000. On Tuesday, the store sold $34,885.21 worth of goods. Find Tuesday's z score. Was Tuesday a significantly good day?

A store manager kept track of the number of newspapers sold each week over a seven-week period. The results are shown below. $\begin{array} { l l l l l l l } 81 & 71 & 202 & 113 & 269 & 248 & 242\end{array}$ Find the median number of newspapers sold.

Explain how two data sets could have equal means and modes but still differ greatly. Give an example with two data sets to illustrate.

The mean of a set of data is 108.06 and its standard deviation is 115.45. Find the z score for a value of 489.67.

In a data set with a range of 55.4 to 105.4 and 400 observations, there are 276 observations with values less than 86. Find the percentile for 86.

Construct a data set for which the range is misleading as a measure of variation. the range is misleading and suggest an alternative measure of variation.

Jorge has his own business as a painter. The amounts he made in the last five months are shown below: $\begin{array} { | l l l l l } \$ 2426 & \$ 2463 & \$ 1451 & \$ 2154 & \$ 1119\end{array}$ Find the mean, median, and range of the data.