Anewspaper reports that the average expenditure on valentine's day is $100.89. do male and female consumers differ in the amounts they spend? the average expenditure in a sample survey of 40 male consumers was $133.67, and the average expenditure in a sample survey of 30 female consumers was $69.64. based on past surveys, the standard deviation for male consumers is assumed to be $45, and the standard deviation for female consumers is assumed to be $20. (a) what is the point estimate (in dollars) of the difference between the population mean expenditure for males and the population mean expenditure for females? (use male − female.) $ 64.03 correct: your answer is correct. (b) at 99% confidence, what is the margin of error (in dollars)? (round your answer to the nearest cent.) $ 20.60 correct: your answer is correct. (c) develop a 99% confidence interval (in dollars) for the difference between the two population means. (use male − female. round your answer to the nearest cent.)