Solved: Use the frequency distribution In Exercise, to

Problem 18E

Use the frequency distribution In Exercise, to construct an expanded frequency distribution, as shown in Example 2.

Reading a Frequency Distribution In Exercise, use the frequency distribution to find the (a) class width, (b) class midpoints, and (c) class boundaries.

Travel Time to Work (in minutes)

Example 2

Finding Midpoints, Relative Frequencies, and Cumulative Frequencies

Using the frequency distribution constructed in Example 1, find the midpoint, relative frequency, and cumulative frequency of each class. Describe any patterns.

Solution

The midpoints, relative frequencies, and cumulative frequencies of the first three classes are calculated as follows.

The remaining midpoints, relative frequencies, and cumulative frequencies are shown in the expanded frequency distribution.

Frequency Distribution for Prices (in dollars) of GPS Navigators

Interpretation There are several patterns in the data set. For instance, the most common price range for GPS navigators is $105 to $144. Also, half of the GPS navigators cost less than $145.

Try It Yourself 2

Using the frequency distribution constructed in Try It Yourself 1, find the midpoint, relative frequency, and cumulative frequency of each class. Describe any patterns.

a. Use the formulas to find each midpoint, relative frequency, and cumulative frequency.

b. Organize your results in a frequency distribution.

c. Describe any patterns in the data.

                                                              Step by Step Solution

Step 1 of 3

We need to find Midpoints, Relative Frequency, and Cumulative Frequency. Then construct an expanded frequency distribution, as shown above.

The midpoint of a class is the sum of the lower and upper limits of the class divided by two, ie;

Midpoint =