Interval	Frequency
Stock analysis. The price-earning ratios of 100 randomly selected stocks from the New York Stock Exchange are:	0.54.5	3
4.59.5	60
9.514.5	21
14.519.5	11
19.524.5	2
24.529.5	1
29.534.5	2

a. Find the mean of the price-earning ratios. (Type an integer or a decimal. Round to two decimal places.)

b. Find the standard deviation of the price-earning ratios. (Type an integer or a decimal. Round to two decimal places.)