The average expenditure on valentine’s day was expected to be $100.89 (usa today, february 13, 2006). do male and female consumers differ in the amounts they spend? the average expenditure in a sample survey of 40 male consumers was $135.67, and theaverage expenditure in a sample survey of 30 female consumers was $68.64. based on pastsurveys, the standard deviation for male consumers is assumed to be $35, and the standarddeviation for female consumers is assumed to be $20.a. what is the point estimate of the difference between the population mean expenditurefor males and the population mean expenditure for females? b. at 99% confidence, what is the margin of error? c. develop a 99% confidence interval for the difference between the two population means.