Please teach me the answers by showing your Excel sheet.

Valentine's Day Expenditures.USA Todayreports 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 $135.67, and the average expenditure in a sample survey of 30 female consumers was $68.64. Based on past surveys, the standard deviation for male consumers is assumed to be $35, and the standard deviation for female consumers is assumed to be $20.

On the basis of above information, answer the following questions:

Qs 1. What is the point estimate of the difference between the population mean expenditure for males and the population mean expenditure for females?

Qs. 2. At 99% confidence, what is the margin of error?

Hint: Margin of error=Z-score multiplied by standard error. The standard error calculation is where most of the mistakes happen, so be very careful with calculation of standard error.

Steps: 1. Take the squares of the standard deviations for two groups and divide them by the respective sample sizes.

Step 2. Add the two numbers you get.

Step 3: Take out the square root to get the standard error.

Step 4 Multiply by z-score (specific to 99% confidence level--google it!) to get the margin of error.

Qs. 3 Develop a 99% confidence interval for the difference between the two population means.