The National Sporting Goods Association (NSGA) conducted a survey of the ages of people that purchased athletic footwear in 2009. The ages are summarized in the following relative frequency distribution.

Age of Purchaser ...Percent

Under 14 years old ....19

14 to 17 years old ..... 6

18 to 24 years old ....10

25 to 34 years old .....13

35 to 44 years old ...14

45 to 64 years old ....25

65 years old and over ...13

Suppose the survey was based on 100 individuals. Calculate the average age of this distribution. Calculate the sample standard deviation. Use 10 as the midpoint of the first class and 75 as the midpoint of the last class.