Page 30 - Sociology and You

1990
2000
School
# Student Body
# Studying Sociology
% Studying Sociology
# Student Body
# Studying Sociology
% Studying Sociology
Cave Spring
928
83
8.9%
1008
164
Glenvar
316
40
421
44
10.5%
Northside
745
52
763
79
Patrick Henry
866
54
6.2%
940
30
William Byrd
643
37
715
55
Wm. Fleming
872
91
948
116
Suppose a group of your friends wanted to compare scores on a college entrance exam. How would you calculate the group’s mean score? Its median score? Its mode score? Which measure would be most meaningful?
Applying the Skill
1. Survey 50 students at your high school to determine their favorite style of music. Based on the results of your survey, determine the percentages of your sample that listed each kind of music as their favorite.
2. Do the results of your survey surprise you? Why or why not?
3. How did you categorize students who named more than one style of
music as their favorite?
Mean, Median, and Mode
The most commonly used summary statistic is the average. Generally speaking, an average is a measure of central ten- dency, indicating where the middle of a series of number lies. There are three ways to compute the average: the mean, median, and mode. The mean is the arithmetic average of a series of items. However, using the mean to represent the average can sometimes be misleading. This generally occurs when a few of the numbers in the series are much higher or lower than the others, resulting in a skewed or biased mean. When this happens, using the median or mode to represent the average may be more meaningful. The median is the mid- point in a series of numbers when they are arranged in order from low to high. The mode is the number that appears most frequently in the series.
Learning the Skill
Follow the steps below to learn how to determine and use measures of cen- tral tendency.
◆ To find the mean, add all of the numbers in the series. Then divide the
sum by the number of observations in the series.
HB-16 Sociology Handbook