4.
An air transport association surveys business travelers to develop quality ratings for transatlantic gateway airports. The maximum possible rating is 10. Suppose a simple random sample of50 businesstravelers is selected and each traveler is asked to provide a rating for a certain airport. The ratings obtained from the sample of50 businesstravelers follow.
Consider the following hypothesis test. Hamil#230 Ha:p1p2>0 The following results are for two independent samples taken from the two populations. mine-:1 Sampfel (a) What is the value of the test statistic? (Round your answer to two decimal places.) : (b) What is the p-value? (Round your answer to four decimal places.) : (c) With a = 0.05, what is your hypothesis testing conclusion? 0 Do not reject Ho- There is insufficient evidence to conclude that \"1 p2 > O. Q Do not Reject HO. There is sufficient evidence to conclude that \"1 p2 : 0. O Reject H0. There is insufcient evidence to conclude that #1 #2 2 0. O Reject H0. There is sufficient evidence to conclude that ,ul pz 3* 0. The following results are for independent random samples taken from two populations. Sample1 Sample? n1=20 n2=30 X1 = 22.6 x2 = 20.1 51 = 2.8 52 = 4.2 (a) What is the point estimate of the difference between the two population means? (Use ;1 7 }2.) \\:l (b) What is the degrees of freedom for the 1.\" distribution? (Round your answer down to the nearest integer.) E (c) At 95% confidence, what is the margin of error? (Round your answer to one decimal place.) :I (d) What is the 95% condence interval for the difference between the two population means? (Use )_(1 7 22. Round your answers to one decimal place.) :lto:l Consider the following data for two independent random samples taken from two normal populations. sampiel 11 6 13 7 9 s Sample 2 8 7 8 3 6 10 (a) Compute the two sample means. 5...... |:I sampne2 E (b) Compute the two sample standard deviations. (Round your answers to two decimal places.) 9...... |:I sampuez |:| (c) What is the point estimate of the difference between the two population means? (Use Sample 1 Sample 2.) E (d) What is the 90% condence interval estimate of the difference between the two population means? (Use Sample 1 Sample 2. Round your answers to two decimal places.) Ste: The increasing annual cost (including tuition, room, board, books, and fees) to attend college has been widely discussed (mecom). The following random samples show the annual cost of attending private and public colleges. Data are in thousands of dollars. Private Colleges Public Colleges 52.8 43.2 45.0 33.3 45.0 20.3 22.0 2812 15.6 24.1 28.5 30.6 44.8 37.8 51.5 42.0 22.8 25.8 18.5 25.6 14.4 21.8 (a) Compute the sample mean (in thousand dollars) and sample standard deviation (in thousand dollars) for private colleges. (Round the standard deviation to two decimal places.) sample mean $\\:| thousand sample standard deviation 3; \\:| thousand Compute the sample mean (in thousand dollars) and sample standard deviation (in thousand dollars) for public colleges. (Round the standard deviation to two decimal places.) sample mean $\\:| thousand sample standard deviation $ \\:| thousand (b) What is the point estimate (in thousand dollars) of the difference between the two population means? (Use Private 7 Public.) $:mousana Interpret this Value in terms of the annual cost (in dollars) of attending private and public colleges. We estimate that the mean annual cost to attend private colleges is 35 Z more than the mean annual cost to attend public college (c) Develop a 95% condence interval (in thousand dollars) of the difference between the mean annual cost of attending private and public colleges. (Use Private 5 Public. Round your answers to one decimal place.) $:mousanato$:mousam 6 4 7 8 6 6 3 10 4 8 7 8 6 5 9 5 8 4 3 8 5 4 4 4 4 8 5 5 7 2 1 5 9 9 9 4 8 9 8 10 O 6 9 7 7 6College Grads High School Grads 501 503 442 492 534 517 580 478 650 526 479 425 554 410 486 485 566 499 528 390 588 562 524 535 497 464 592 469
