USA Today reports that the average expenditure on Valentine's Day was expected to be $100.89. Do male and female consumers differ in the
amounts they spend? The average expenditure in a sample survey of 46 male consumers was $130.84, and the average expenditure in a sample
survey of 32 female consumers was $64.87. Based on past surveys, the standard deviation for male consumers is assumed to be $32, and the
standard deviation for female consumers is assumed to be $20. 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 error?
c. Develop a 99% confidence interval for the difference between the two population means.
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