INTERPRETING STEM AND LEAF PLOTS WORKSHEET

Problem 1 :

The stem-and-leaf plot shows student test scores.

(a) How many students scored less than 80 points?

(b) How many students scored at least 90 points?

(c) How are the data distributed?

Solution

Problem 2 :

Which statement is not true?

A) Most of the plants are less than 20 inches tall.

B) The median plant height is 11 inches.

C) The range of the plant heights is 35 inches.

D) The plant height that occurs most often is 11 inches

Solution

Problem 3 :

Use the stem-and-leaf plot at the right.

1. How many data values are in the set?

2. What is the least value? greatest value?

3. What is the median? range?

4. Is the value 32 in the set? Explain.

Solution

Problem 4 :

Describe and correct the error in making a stem-and-leaf plot of the data.

51, 25, 47, 42, 55, 26, 50, 44, 55

Solution

Problem 5 :

The weights (in pounds) of eight puppies at a pet store are

12, 24, 17, 8, 18, 31, 24, and 15.

Make a stem-and-leaf plot of the data. Describe the distribution of the data.

Solution

Problem 6 :

The stem-and-leaf plot shows the number of digs for the top 15 volleyball players at a recent women’s AVP Miami Open.

1. How many players had more than 60 digs?

2. Find the mean, median, mode, and range of the data.

3. Describe the distribution of the data.

4. Which data value is the outlier? Describe how the outlier affects the mean.

Solution

Problem 7 :

1. Determine the minimum value, maximum value and range of the data.

2. How many values are greater than 190?

3. Determine the count, median, mode and mean of the data. Round the mean to one decimal place if necessary

4. How many values are less than 151?

Solution

Answer Key

1)  a)  5 students has scored less than 80 points.

b)  4 students has scored at least 90.

c) The distribution is symmetric.

2)  Option B is not correct.

3)  1) There are 11 values in the data set.

2)  Least value = 4 and greatest value = 42

3) 24 is the median, Range = 38

4) 32 is not in the data set.

4)  One more stem should be included. Then the corrected stem and leaf plot will be 

5)  

The least weight of the pet is 8 pounds. The distribution is symmetric.

6)

1) 6 players had more than 60 digs.

2)  Median = 53, Modes are 41, 43 and 63, range = 56

3) The data is symmetric to the right.

4) Outlier is 97.

7)

1. Minimum value = 131 and maximum value = 228

2. 7 values are greater than 190.

3. Mean = 92

4. 5 values are lesser than 151.