Advertising expenses are significant component of the cost of goods sold. Listed below is a frequency distribution showing the advertising expenditures for 60 manufacturing companies located in the Southwest. Estimate the mean and the standard deviation of advertising expense.

Advertising expenses are significant component of the cost of goods sold. Listed below is a frequency distribution showing the advertising expenditures for 60 manufacturing companies located in the Southwest. Estimate the mean and the standard deviation of advertising expense.

Advertising Expenditure
($ millions) Number of Companies
25 up to 35 5
35 up to 45 10
45 up to 55 21
55 up to 65 16
65 up to 75 8
Total 60