# Frequency distribution, stem and leaf plot, statistical graphs

1. The acreage of the 39 U.S. National Parks under 900,000 acres (in thousands of acres) is shown here. Construct a frequency distribution for the data using eight classes. Do a frequency distribution, you are constructing a table, not a graph.

41 66 233 775 169

36 338 233 236 64

183 61 13 308 77

520 77 27 217 5

650 462 106 52 52

505 94 75 265 402

196 70 132 28 220

760 143 46 539

2. The data shown represent the percentage of unemployed males and females in the 1995 for a sample of countries of the world. Using the whole numbers as stems and the decimals as leaves, construct a back-to-back stem and leaf plot and compare the distributions of the two groups. Draw a graph. State one salient finding.

Females Males

8.0 3.7 8.6 5.0 7.0 8.8 1.9 5.6 4.6 1.5

3.3 8.6 3.2 8.8 6.8 2.2 5.6 3.1 5.9 6.6

9.2 5.9 7.2 4.6 5.6 9.8 8.7 6.0 5.2 5.6

5.3 7.7 8.0 8.7 0.5 4.4 9.6 6.6 6.0 0.3

6.5 3.4 3.0 9.4

3. State which graph (Pareto chart, time series graph or pie graph) would most appropriately represent the given:

a. The number of students enrolled at a local college for each year during the last 5 years.

b. The budget for the student activities department at a certain college for each year during the last 5 years.

c. The means of transportation the students use to get to school.

d. The percentage of votes each of the four candidates received in the last election.

e. The record temperatures of a city for the last years.

f. The frequency of each type of crime committed in a city during the year.

3. Make a graph. Then, answer the question. The number of successful space launches by the United States and Japan for the years 1993 - 1997 is shown here. Construct a compound time series graph for the data. What comparison can be made regarding the launches?

Year 1993 1994 1995 1996 1997

United States 29 27 24 32 37

Japan 1 4 4 1 2

4. Make a graph, then, describe the nature of the relationship. A researcher wishes to determine if there is a relationship between the number of days an employee missed a year and the person's age. Draw a scatter plot and comment on the nature of the relationship.

Age, x 22 30 25 35 65 50 27 53 42 58

Days missed, y 0 4 1 2 14 7 3 8 6 4

5. Draw a graph, then, describe the nature of the relationship. These data represent the ages of the drivers and the number of accidents reported for each age group in Pennsylvania for a selected year. Draw a scatter plot and describe the nature of the relationship.

Age,x 16 17 18 19 20 21

# of accidents, y 6605 8392 8506 7349 6458 5974

#### Solution Summary

This solution answers several statistical problems, for example about frequency distribution, stem and lead plots and various statistical graphs.