Q: What is the class width if the lowest value in a data set is 5, the highest value is 89, and you want 7 classes?

$$\text{Class width} = \frac{89 - 5}{7} = 12 ($$rounded up to 15)

Q: Which of the following is the correct formula for class width in a frequency distribution?

$$\text{Class width} = \frac{\text{Maximum value} - \text{Minimum value}}{\text{Number of classes}}$$

Question 1

Which of the following best describes a frequency distribution?

Accepted Answer

A table that shows how data are partitioned among several categories by listing the categories along with the number of data values in each.

Question 2

How is the class midpoint for a frequency distribution calculated?

Accepted Answer

By adding the lower class limit to the upper class limit and dividing by 2: $$\frac{	ext{Lower class limit} + 	ext{Upper class limit}}{2}$$

Question 3

What is the class width if the lowest value in a data set is 5, the highest value is 89, and you want 7 classes?

Accepted Answer

$$	ext{Class width} = \frac{89 - 5}{7} = 12 ($$rounded up to 15)

Question 4

Which of the following statements about relative frequency distributions is TRUE?

Accepted Answer

Relative frequency distributions replace class frequencies with proportions or percentages.

Question 5

A cumulative frequency distribution is best described as:

Accepted Answer

A table where each class frequency is the sum of the frequencies for that class and all previous classes.

Question 6

If a frequency distribution has frequencies that start low, increase to a maximum, and then decrease, and is approximately symmetric, what type of distribution does it suggest?

Accepted Answer

A normal distribution

Question 7

What does the presence of a large gap in a frequency distribution most likely indicate?

Accepted Answer

That the data may be from two or more different populations.

Question 8

Which of the following is the correct formula for class width in a frequency distribution?

Accepted Answer

$$	ext{Class width} = \frac{	ext{Maximum value} - 	ext{Minimum value}}{	ext{Number of classes}}$$

Question 9

Suppose you are comparing the relative frequency distributions of commute times in two cities. City A has 75% of commutes in the lowest two classes, while City B has only 30% in the same classes. What can you conclude?

Accepted Answer

City A has generally shorter commute times than City B.

Question 10

Which of the following is NOT a step in constructing a frequency distribution?

Accepted Answer

Calculating the mean and median of the data.

Question 11

If the lower class limits of a frequency distribution are 0, 15, 30, 45, 60, what is the class width?

Accepted Answer

$$15$$

Question 12

Why is it important to round up the class width when constructing a frequency distribution?

Accepted Answer

To ensure that all data values are included in the classes.

Question 13

Which of the following best describes class boundaries?

Accepted Answer

Numbers used to separate classes without gaps created by class limits.

Question 14

A frequency distribution for the weights of pennies shows a large gap between two groups. What is the most reasonable explanation?

Accepted Answer

There are two different populations of pennies, likely due to a change in composition.

Question 15

Which of the following is a critical use of frequency distributions in statistics?

Accepted Answer

To determine whether the data have a normal distribution.

Exploring Data with Tables and Graphs: Frequency Distributions and Data Visualization

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