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 44 male consumers was $138.76 , and the average expenditure in a sample survey of 36 female consumers was $61.13 . Based on past surveys, the standard deviation for male consumers is assumed to be$31 , 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.
What is the point estimate of the difference between the population mean expenditure for males and the population mean expenditure for females?
At confidence, 99% what is the margin of error?
Develop a 99% confidence interval for the difference between the two population means. ____ to ______.
