Basic Mathematics for College Students

Chapter 7 Summary and Review 627

SECTION 7.2 Mean, Median, and Mode

It is often beneficial to use one number to

represent the “center” of all the numbers in a

set of data. There are three measures ofcentral

tendency:mean, median, mode.

The meanof a set of values is given by the

formula

Mean

sum of the values

number of values

DEFINITIONS AND CONCEPTS EXAMPLES

Find the mean of the following set of values:

68359810785

To find the mean, we divide the sum of the values by the number of

values, which is 10.

Thus, 6.9 is the mean.

6.9

6  8  3  5  9  8  10  7  8  5

10



69

10

26. How many more eggs did Nebraska produce in 2000
    compared to North Carolina?

A survey of the weekly television viewing habits of 320

households produced the histogram in the next column. Use the

graph to answer the following questions.

27. How many households watch between 1 and 5 hours
    of TV each week?


28. How many households watch between 6 and 15
    hours of TV each week?

2,500

2,600

2,700

2,800

2,900

Million eggs

3,000

3,100

3,200

3,300

2000 2001

Source: U.S. Department of Agriculture

2002 2003

Total Egg Production

2004

Year

2005 2006 2007 2008

North Carolina

Nebraska

29. How many households watch 11 hours or more each
    week?


30. Create a frequency polygon from the histogram
    shown above.

3.0 8.0 13.0 18.0 23.0

Hours of TV watched by the household

Frequency

10

30

50

70

90

110

Survey of Hours of TV Watched Weekly

10

0.5 5.5 10.5 15.5 20.5 25.5

Hours of TV watched by the household

30

50

70

Frequency

90

110