The National Sporting Goods Association (NSGA) conducted a survey of the ages of individuals that purchased skateboarding footwear. The ages

The National Sporting Goods Association (NSGA) conducted a survey of the ages of individuals that purchased skateboarding footwear. 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

Required:
Calculate the mean and the standard deviation of the age of individuals that purchased skateboarding shoes. Use 10 as the midpoint of the first class.