Question

You may need to use the appropriate appendix table or technology to answer this question A newspaper 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 $135.67, and the average expenditure in a sample survey of 30 female consumers was $67.64. 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. (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) $ (b) At 99% confidence, what is the margin of error in dollars)? (Round your answer to the nearest cont.) $ (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 cont.) to $

Answer 1

a x = 135.67 x = 67.64 6=35 2 = 20 Given n = 40 12=30 a) Point estimate for difference between the 'means X-X2 - 135-67-67:64 = 68.03 x - 72 = 68.03 b) Margin of 2 at gg - n2 =0.5 /. 4/2 2012 2.58 2.58 35² + 202 = 2.58/30.6257 13 333333 40 30 2.58 x 43.9583333 Margin of error = 17. 1056789 Margin of error $17011 c) gg7 CI X-X2 I Margin of error 68.03 I 17.1056 7 8 9 5019243211, 85.1356789 { $50.92 $85.14)