Question

the stem-and-leaf plot below gives the test scores for the 16 students in mr. jones math class. use the plot to answer the questions that follow.
test score
key: 6|5 means a score of 65.
6 5 6
7 1 5 6 9
8 0 1 3 5 6 7 9
9 1 7 8
(a) how many students scored in the 80s?
(b) what was the lowest score in the 70s?
(c) what was the highest score overall?

Explanation:

Part (a)

Step1: Identify the stem for 80s

The stem for scores in the 80s is 8 (since the stem represents the tens place).

Step2: Count the leaves for stem 8

Looking at the stem - and - leaf plot, for stem 8, the leaves are 0, 1, 3, 5, 5, 6, 7, 9. Let's count the number of leaves. We can see that there are 8 leaves. Each leaf represents a student's score in the 80s (e.g., 8|0 means 80, 8|1 means 81, etc.). So the number of students who scored in the 80s is the number of leaves for stem 8.

Step1: Identify the stem for 70s

The stem for scores in the 70s is 7 (the tens place).

Step2: Find the smallest leaf for stem 7

For stem 7, the leaves are 1, 5, 5, 6, 9. The smallest leaf is 1. So the lowest score in the 70s is formed by the stem 7 and the smallest leaf 1, which is 71.

Step1: Identify the largest stem

The stems in the stem - and - leaf plot are 6, 7, 8, 9. The largest stem is 9.

Step2: Find the largest leaf for stem 9

For stem 9, the leaves are 1, 7, 8. The largest leaf is 8. So the highest score overall is formed by the stem 9 and the largest leaf 8, which is 98.

Answer:

8

Part (b)