Question

use the frequency histogram to complete the following parts.
(a) determine the number of classes.
(b) estimate the greatest and least frequencies.
(c) determine the class width.
(d) describe any patterns with the data.
histogram titled employee salaries with x - axis salary (in thousands of dollars) (labels include 35, 37, 42, 47, 52, 57, 62) and y - axis frequency (ranging from 0 to 300) showing blue bars for different salary intervals

Explanation:

Part (a)

Step1: Identify bars in histogram

Count the number of blue bars (classes) in the histogram.
Looking at the x - axis labels (15, 17, 42, 47, 52, 57, 62) and the bars, we can see there are 7 bars.

Step1: Estimate greatest frequency

Look at the tallest bar. The tallest bar seems to reach up to around 300 (from the y - axis scale).

Step2: Estimate least frequency

Look at the shortest bar. The shortest bar (first bar) seems to be around 20 (from the y - axis scale).

Step1: Find class boundaries

Take two consecutive class mid - points or use the x - axis values. Let's take the first two non - zero x - axis values (assuming the first class is around 15 - 20? Wait, looking at the x - axis labels: 15, 17, 42, 47, 52, 57, 62. Wait, maybe the class width is calculated as the difference between consecutive class marks. Let's take 17 - 15? No, maybe the classes are: Let's see the difference between 47 and 42 is 5, 52 - 47 is 5, 57 - 52 is 5, 62 - 57 is 5. Wait, maybe the first two classes: 15 - 20? No, the x - axis labels are 15, 27? Wait, maybe a typo, maybe 27 instead of 17? Wait, no, looking at the histogram, the x - axis has labels 15, 27 (maybe 27), 42, 47, 52, 57, 62. Wait, no, let's calculate the class width as the difference between consecutive class intervals. Let's take the middle classes: 42 to 47: 47 - 42 = 5, 47 to 52: 52 - 47 = 5, 52 to 57: 57 - 52 = 5, 57 to 62: 62 - 57 = 5. So the class width is 5.

Answer:

The number of classes is 7.

Part (b)