2. The Port Authority sells a wide variety of cables and adapters for electronic equipment online. Last year the mean value of orders placed with the Port Authority was $47.28, and management wants to assess whether the mean value of orders placed to date this year is the same as last year. The values of a sample of 49,896 orders placed this year are collected and recorded in the file PortAuthority. (20 points). a. Formulate hypotheses that can be used to test whether the mean value of orders placed this year differs from the mean value of orders placed last year. (10 points). b. Use the data in the file PortAuthority to conduct your hypothesis test. What is the p value for your hypothesis test? At =0.01, what is your conclusion? (10 points). 3. The Intemational Air Transport Association surveys business travelets to develop quality ratings for transatlantic gateway airports. The maximum possible rating is 10 . Suppose a simple random sample of 50 business travelers is selected and each traveler is asked to provide a rating for the Miami International Airport (Data file-Miami). Develop a 95% confidence interval estimate of the population mean rating for Miami. (20 points). 4. The Toyota Camry is one of the best-selling cars in North America. The cost of a previously owned Camry depends on many factors, including the model year, mileage, and condition. To investigate the relationship between the car's mileage and the sales price for Camrys, the dataset Camry shows the mileage and sale price for 19 sales. (20 points). 1 a. Develop a scatter chart for these data with miles as the independent variable. What does the scatter chart indicate about the relationship between price and miles? (5 points). b. Develop an estimated regression equation showing how price is related to miles. What is the estimated regression model? ( 5 points). c. Test whether each of the regression parameters 0 and 1 is different from zero at a 0.01 level of significance. Interpret the estimated regression parameters. ( 5 points). d. How much of the variation in the sample values of price does the model estimated in part (b) explain? (5 points). 4. The Toyota Camry is one of the best-selling cars in North America. The cost of a previously owned Camry depends on many factors, including the model year, mileage, and condition. To investigate the relationship between the car's mileage and the sales price for Camrys, the dataset Canry shows the mileage and sale price for 19 sales. (20 points). 1 a. Develop a scatter chart for these data with miles as the independent variable. What does the seatter chart indicate about the relationship between price and miles? (5 points). b. Develop an estimated regression equation showing how price is related to miles. What is the estimated regression model? (5 points). c. Test whether each of the regression parameters 0 and 1 is different from zero at a 0.01 level of significance. Interpret the estimated regression parameters. ( 5 points). d. How much of the variation in the sample values of price does the model estimated in part (b) explain? ( 5 points). 5. Resorts \& Spas, a magazine devoted to upscale vacations and accommodations, published its Reader's Choice List of the top 20 independent beachfront boutique hotels in the world. The data in the file BeachFrontholels are the scores received by these hotels based on the results from Resorts \& Spas " annual Readers' Choice Survey. Fach seore represents the percentage of respondents who rated a botel as excellent or very good on one of three criteria (comfort, amenities, and in-house dining). An overall score was also reported and used to rank the hotels. The highest ranked hotel, the Muri Beach Odysscy, has an overall score of 94.3 , the highest component of which is 97.7 for in-house dining. (20 points). a. Determine the estimated multiple linear regression equation that can be used to predict the overall score given the seores for comfort, amenities, and in-house dining. (5 points). b. Test the significance of the overall regression relationship (from the model used in (a)) at 1%,5%, and 10% levels of significance. ( 5 points). c. Test the significance of each independent variable at the 0.01 level of significance (from the model used in (a)). ( 5 points). d. Remove all independent variables that are not significant at the 0.01 level of significance from the estimated regression equation. What is the new estimated regression equation? ( 5 points). \begin{tabular}{|c|c|} \hline \begin{tabular}{c} Miles \\ (1000s) \end{tabular} & \begin{tabular}{c} Price \\ ($1000s) \end{tabular} \\ \hline 22 & 16.2 \\ \hline 29 & 16.0 \\ \hline 36 & 13.8 \\ \hline 47 & 11.5 \\ \hline 63 & 12.5 \\ \hline 77 & 12.9 \\ \hline 73 & 11.2 \\ \hline 87 & 13.0 \\ \hline 92 & 11.8 \\ \hline 101 & 10.8 \\ \hline 110 & 8.3 \\ \hline 28 & 12.5 \\ \hline 59 & 11.1 \\ \hline 68 & 15.0 \\ \hline 68 & 12.2 \\ \hline 91 & 13.0 \\ \hline 42 & 15.6 \\ \hline 65 & 12.7 \\ \hline 110 & 8.3 \\ \hline \end{tabular} \begin{tabular}{|l|r|r|r|r|} \hline Hotel & Overall & Comfort & Amenities & In-House Dining \\ \hline Muri Beach Odyssey & 94.3 & 94.5 & 90.8 & 97.7 \\ \hline Pattaya Resort & 92.9 & 96.6 & 84.1 & 96.6 \\ \hline Sojourner's Respite & 92.8 & 99.9 & 100.0 & 88.4 \\ \hline Spa Carribe & 91.2 & 88.5 & 94.7 & 97.0 \\ \hline Penang Resort and Spa & 90.4 & 95.0 & 87.8 & 91.1 \\ \hline Mokihana Hkele & 90.2 & 92.4 & 82.0 & 98.7 \\ \hline Theo's of Cape Town & 90.1 & 95.9 & 92.5 & 91.9 \\ \hline Cap d'Agde Resort & 89.8 & 92.5 & 85.8 & 88.8 \\ \hline Spirit of Mykonos & 89.3 & 94.6 & 83.2 & 90.7 \\ \hline Turismo del Mar & 89.1 & 90.5 & 81.9 & 90.4 \\ \hline Hotel Iguana & 89.1 & 90.8 & 93.0 & 88.5 \\ \hline Sidi Abdel Rahman Palace & 89.0 & 93.0 & 78.2 & 89.6 \\ \hline Sainte-Maxime Quarters & 88.6 & 92.5 & 91.6 & 91.2 \\ \hline Rotorua Inn & 87.1 & 93.0 & 74.9 & 73.5 \\ \hline Club Lapu-Lapu & 87.1 & 90.9 & 78.0 & 89.6 \\ \hline Terracina Retreat & 86.5 & 94.3 & 77.3 & 91.5 \\ \hline Hacienda Punta Barco & 86.1 & 95.4 & 76.4 & 90.8 \\ \hline Rendezvous Kolocep & 86.0 & 94.8 & 72.2 & 91.4 \\ \hline Cabo de Gata Vista & 86.0 & 92.0 & 77.3 & 89.2 \\ \hline Sanya Deluxe & 85.1 & 93.4 & 91.8 \\ \hline \end{tabular}