Test Bank For Preliminary Edition of Statistics Learning from Data 1st Edition by Roxy Peck

Chapter 2: Graphical Methods for

Describing Data Distributions Concept Quiz

Name _________________________

The answers to the questions below frequently depend on remembering facts, under- standing concepts, and knowing statistical vocabulary. Before answering, be sure to read carefully!

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A univariate data set must contain numerical, not categorical, data.

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A pie chart is most useful for numeric data.
In a histogram, class intervals are required to be the same length. A bar chart is a graphical display of categorical data.

In a scatter plot, both the horizontal and vertical axes must start at zero.

A unimodal set of data is one that contains only one variable.

Chapter 2, Concept Quiz Page 1 of 1

If the upper tail of a distribution stretches out farther than the lower tail, the distribution is negatively skewed.

Chapter 2, Concept Quiz

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Answer Key

Chapter 2, Concept Quiz

Answer Key

Page 1 of 1

Chapter 2: Graphical Methods for

Describing Data Distributions Section 2.1-2.3

Name ___________________________

1. The article “New Rules Would Protect Students” (USA Today, June 16, 2010) reported the percentage of students who received loans to attend college that had defaulted on the loan within 3 years of when the student was scheduled to begin repayment of the loan. Information was given for public colleges, private non-profit colleges, and for-profit colleges.

Loan Status

Good Standing In Default

Public Colleges

.928 .072

Relative Frequency Private Non-profit Colleges
.953
.047

For-Profit Colleges

.833 .167

a) Construct a comparative bar chart that would allow you to compare loan status for the three types of colleges.

b) The article states “those who attended for-profit schools were more likely to default than those who attended public or private non-profit schools.” What aspect of the comparative bar chart supports this statement?

Chapter 2, Quiz 1, Form A Page 1 of 4

2. The stem-and-leaf plot below displays the weights (in ounces) for a random sample of tomatoes grown on a local farm

Weights of Tomatoes (oz)

2L|4
2H|
3L|2
3H|89
4L|13
4H|5589
5L|11122334
5H|668999
6L|223344
6H|5556

stem: ones
leaf: tenths

(a) Briefly describe the distribution of tomato weights.

(b) What is the weight of the heaviest tomato in the sample?

Chapter 2, Quiz 1, Form A Page 2 of 4

3. Knowledge of where animals forage for food is essential for effective wildlife management and conservation. The data below are foraging heights (in m) for a sample of Mountain Chickadees. The data are taken from two different species of fir trees: the Douglas fir and the White fir.

Douglas: 22, 15, 16, 16, 16, 17, 17, 17, 18, 19, 19, 10, 10, 13, 13, 14 6,7, 7,8,8,9,3

White: 28, 25, 21, 21, 18, 18, 16, 14, 14, 15, 15, 15, 15, 12, 12, 13 13,11,11, 8, 8, 7, 5, 3

(a) Display these data using a comparative (back-to-back) stem-and-leaf plot. Use the stems shown below, and be sure to include all information needed to compare the two distributions.

                   |0L|
                   |0H|
                   |1L|
                   |1H|
                   |2L|
                   |2H|

Chapter 2, Quiz 1, Form A Page 3 of 4

(b) Compare the distributions in part (a). What differences and similarities do you observe in the two distributions?

(c) When Mountain Chicadees are sampled to assess their health, they are captured in mist-nets, which are set to capture the birds at different heights. The mist nets are about 2 meters high, and directions must be given to the persons who set up the nests so that the mist-nets are positioned to capture the most birds. Based on the data from part (a) and your display in part (b), write a short paragraph describing the appropriate mist-net height in a forest region of Douglas firs and for a forest region of White firs.

Chapter 2, Quiz 1, Form A Page 4 of 4