Question 1

Which of the following best describes a dot plot for a quantitative data set?

Accepted Answer

A plot where each data value is represented by a dot on a horizontal scale, with repeated values stacked vertically.

Question 2

Given the stem-and-leaf display below, what is the smallest value in the data set?

$$\begin{array}{l}
2 \quad 30 \quad 0 \
2 \quad 31 \quad 8 \
\end{array}$$

Accepted Answer

$$30.0$$

Question 3

Which graphical method would be most appropriate for quickly identifying the mode in a small quantitative data set?

Accepted Answer

Dot plot

Question 4

In a histogram, what does the total area under the bars represent?

Accepted Answer

The total relative frequency, which is always $$1.$$

Question 5

Suppose you have a data set with $$100$$ observations. According to the guidelines, how many class intervals should you use when constructing a histogram?

Accepted Answer

$$15 to$$ $$20$$

Question 6

Which of the following statements about stem-and-leaf plots is TRUE?

Accepted Answer

They preserve the original data values and show the distribution shape.

Question 7

A histogram for a very large data set with very narrow class intervals will most closely resemble:

Accepted Answer

A smooth curve

Question 8

If the relative frequency for the class interval $$37-38 in a $$histogram is $$0.20$$, what does this mean?

Accepted Answer

20% of the data values fall within the interval $$37-38.$$

Question 9

Which of the following is a key advantage of a stem-and-leaf plot over a histogram?

Accepted Answer

It allows you to recover the original data values.

Question 10

A researcher collects the following deviations (in degrees) from a water-level task: $$-9, 6, 10, 6, 10, 3, 7, 8, 6, 14. $$Which graphical method would best display the symmetry or skewness of this data?

Accepted Answer

Histogram

Question 11

If you change the definition of the 'stem' in a stem-and-leaf plot from the tens and ones digits to just the tens digit, what effect does this have?

Accepted Answer

It increases the number of leaves per stem, making the plot more compact.

Question 12

Which of the following is NOT a characteristic of a histogram?

Accepted Answer

It displays individual data values.

Question 13

A dot plot of EPA mileage ratings for $$100$$ cars shows most dots clustered between $$35$$ and $$39$$ MPG. What does this indicate about the distribution?

Accepted Answer

The data is concentrated around the center, suggesting a symmetric distribution.

Question 14

Which of the following best describes the process of constructing a histogram?

Accepted Answer

Partition the data into equal-width intervals, count the frequency in each interval, and draw bars with heights proportional to the frequencies.

Question 15

A histogram for a data set is right-skewed. Which of the following is most likely true?

Accepted Answer

Most data values are concentrated on the left, with a few larger values stretching to the right.

Question 16

Which graphical method would be LEAST appropriate for summarizing the EPA mileage ratings of $$100$$ cars?

Accepted Answer

Pie chart

Question 17

Suppose you have the following stem-and-leaf display for deviations: 
$$0 \mid 002234$$ 
How many data values are between $$0$$ and $$0.9$$ degrees?

Accepted Answer

$$6$$

Question 18

A histogram is constructed for a data set of $$40$$ water-level task deviations. If the number of classes is set too low, what is a likely consequence?

Accepted Answer

The histogram will be too coarse, possibly hiding important features of the data.

Question 19

Which of the following is a correct interpretation of the area above a class interval in a relative frequency histogram?

Accepted Answer

It represents the proportion of data values in that interval.

Question 20

If you want to compare the distributions of deviations for bartenders and waitresses, which graphical method is most effective?

Accepted Answer

A side-by-side histogram

Graphical Methods for Describing Quantitative Data

Study Guide - Practice Questions

Study Guide - Flashcards