The National Sporting Goods Association (NSGA) conducted a survey of the ages of individuals that purchased skate boarding foot-wear. The ages of this survey are summarized in the following percent frequency distribution. Assume the survey was based on a sample of 200 individuals. Age of User Percent
Under 14 years old 34
14 to 17 years old 39
18 to 24 years old 17
25 to 34 years old 4
35 to 44 years old 3
45 to 64 years old 3
Calculate the mean and the standard deviation of the age of individuals that purchased skate boarding shoes. Use 10 as the midpoint of the first class.
A. Mean.
B. Variance.
C. Standard deviation.