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 $138.67, 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 $45, and the standard deviation for female consumers is assumed to be $20.

1. 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.) $------ to$------

Periodically, customers of a financial services company are asked to evaluate the company's financial consultants and services. Higher ratings on the client satisfaction survey indicate better service, with 7 the maximum service rating. Independent samples of service ratings for two financial consultants are summarized here. Consultant A has 10 years of experience, whereas consultant B has 1 year of experience. Use a = 0.05 and test to see whether the consultant with more experience has the higher population mean service rating. Consultant A Consultant B n1 = 16 n, = 10 x, = 6.85 x2 = 6.26 51 = 0.69 $2 = 0.75 (a) State the null and alternative hypotheses. OHO: H1 - H2 0 Ha: H1 - H2 = 0 OH: H1 - H250 Ha: H 1 - H2> 0 O HO: H1 - H2= 0 Ha: H 1 - H2 + 0 O Ho: H1 - H2 0 Ha : H1 - H2 = 0 O Ho: M1 - H2 2 0 Ha: H1 - H2 SO S (b) Compute the value of the test statistic. (Round your answer to three decimal places.) (c) What is the p-value? (Round your answer to four decimal places.) p-value = (d) What is your conclusion? Reject Ho. There is insufficient evidence to conclude that the consultant with more experience has a higher population mean rating. O Do not Reject Ho. There is sufficient evidence to conclude that the consultant with more experience has a higher population mean rating. O Do not reject Ho. There is insufficient evidence to conclude that the consultant with more experience has a higher population mean rating. O Reject H . There is sufficient evidence to conclude that the consultant with more experience has a higher population mean rating.A manufacturer produces both a deluxe and a standard model of an automatic sander designed for home use. Selling prices obtained from a sample of retail outlets follow. Model Price ($) Retail Outlet Deluxe Standard Sta 39 27 2 38 29 44 35 4 38 30 Q 5 40 30 6 39 35 A 35 29 (a) The manufacturer's suggested retail prices for the two models show a $10 price differential. Use a 0.05 level of significance and test that the mean difference between the prices of the two models is $10. State the null and alternative hypotheses. (Use / = mean price for the deluxe model - mean price for the standard model.) O Ho: Mg > 10 Ha Ha S 10 O Ho: Ha S 10 Hai Ha > 10 Stat O Ho: My = 10 Ha: Ha S 10 O Ho: Hd # 10 Ha Ha = 10 O Ho: Hd = 10 Ha: Hy # 10 Q Calculate the value of the test statistic. (Round your answer to three decimal places.) A Calculate the p-value. (Round your answer to four decimal places.) p-value = State your conclusion. Do not reject Ho. There is insufficient evidence to conclude that a $10 price differential exists. Reject Ho. There is sufficient evidence to conclude that a $10 price differential exists. Reject Ho. There is insufficient evidence to conclude that a $10 price differential exists. Stat Do not Reject Ho. There is sufficient evidence to conclude that a $10 price differential exists. (b) What is the 95% confidence interval for the difference between the mean prices of the two models (in dollars)? (Round your answers to nearest cent. Use the mean price for the deluxe model - the mean price for the standard model.) to $