Advertising expenses are a significant component of the cost of goods sold. Listed below ...

     Advertising   expenses are a significant component of the cost of goods sold. Listed below   is a frequency distribution showing the advertising expenditures for 70   manufacturing companies located in the Southwest. The mean expense is $50.71   million and the standard deviation is $11.59 million. Is it reasonable to   conclude the sample data are from a population that follows a normal   probability distribution?    

      Advertising Expense Number   ($ Million) of Companies     25 up to 35 7     35 up to 45 14     45 up to 55 25     55 up to 65 15     65 up to 75 9   Total 70