Question

Mr. Jacobs is going to make a histogram of the test scores from the last math test he gave. He plans to first organize the data into a stem-and-leaf plot and then make the histogram from the stem-and-leaf plot. The test scores are listed below. 79, 82, 65, 61, 94, 97, 84, 77, 89, 91, 90, 83, 99, 71, 68, 77, 87, 85 Which of the following expressions could be used to find how many students scored less than a 90 on the test?
3 + 44 + 63 + 4 + 63 + 4 + 6 + 1

Answer 1

The stem and leaf plot will look like:
6 | 1 5 8 - 3 scores
7 | 1 7 7 9 - 4 scores
8 | 2 3 4 5 7 9 - 6 scores
9 | 0 1 4 7 9 - 1 score
To total up the number of students who scored less than 90, we have 3 under 60-69, 4 under 70-79, and 6 under 80-89, so this is 3 + 4 + 6. This is the third choice.