USA Today reports that the average expenditure on Valentine's Day was expected to be $100.89, Do male and female consur ler in the amounts they spend? The average expenditure in a sample survey of 58 male consumers was $134.07, and the average expenditure in a sample survey of 33 female consumers was $64.5, Based on past surveys, the standard deviation for male consumers is assumed to be $30, and the standard deviation for female consumers is assumed to be $14, The z value is 2.576 . Round your answers to 2 decimal places. a. What is the point estimate of the difference between the population mean expenditure for males and the population mean expenditure for females? b. At 99% confidence, what is the margin of erron? c. Develos a 99% confidence interval for the difference between the two population means