At the end of a certain year, the four companies with the largest number of home Internet users in the United States were Microsoft, Time Warner, Yahoo, and Google, with a combined audience of 284 million users. Taking x to be the Microsoft audience in millions, y the Time Warner audience in millions, z the Yahoo audience in millions, and u the Google audience in millions, it was observed that           z  −  u  =  3(x − y) + 10           x  +  y  =  50 + z + u and   x  −  y  +  z  −  u  =  46. How large was the audience of each of the four companies at the end of that year?

A researcher believed that the number of rental cars in service by a car rental company would have an impact on the total annual revenue for that car rental company. Five small car rental companies were surveyed, with the number of Cars in service recorded in units of 1000 (so if a car rental company had 54000 cars in service, a 54 would be recorded) and Annual Revenue measured in millions of dollars (so an Annual Revenue of $10,000,000 would be recorded as 10). The data follows: Cars (1,000s)       Annual Revenue ($ millions)11.5                   118 10.0                   135 9.0                     100 5.5                     37 3.3                     32 Part of the Excel-generated Simple Linear Regression output is provided below: ANOVA   df SS MS F Significance F Regression 1 7891.863897 7891.863897 22.91180151 0.017339231 Residual 3 1033.336103 344.4453677     Total 4 8925.2           Coefficients Standard Error t Stat P-value Intercept -19.12490108 23.1658578…

A motion picture industry analyst is studying movies based on epic novels. The following data were obtained for 10 Hollywood movies made in the past five years. Each movie was based on an epic novel. For these data, x1 = first-year box office receipts of the movie, x2 = total production costs of the movie, x3 = total promotional costs of the movie, and x4 = total book sales prior to movie release. All units are in millions of dollars. x1 x2 x3 x4 85.1 8.5 5.1 4.7 106.3 12.9 5.8 8.8 50.2 5.2 2.1 15.1 130.6 10.7 8.4 12.2 54.8 3.1 2.9 10.6 30.3 3.5 1.2 3.5 79.4 9.2 3.7 9.7 91.0 9.0 7.6 5.9 135.4 15.1 7.7 20.8 89.3 10.2 4.5 7.9   a) Find a 90% confidence interval for each coefficient. (Use 2 decimal places.)   lower limit upper limit ?2     ?3     ?4     b) Suppose a new movie (based on an epic novel) has just been released. Production costs were x2 = 11.4 million; promotion costs were x3 = 4.7 million; book sales were x4 = 8.1 million. Make a…

The owner of a chain of mini-markets wants to compare the sales performance of two of her stores, Store 1 and Store 2. Though the two stores have been comparable in the past, the owner has made several improvements to Store 1 and wishes to see if the improvements have made Store 1 more popular than Store 2. Sales can vary considerably depending on the day of the week and the season of the year, so she decides to eliminate such effects by making sure to record each store's sales on the same 12 days, chosen at random. She records the sales (in dollars) for each store on these days, as shown in the table below. Day 1 2 3 4 5 6 7 8 9 10 11 12 Store 1 944 462 984 958 457 250 726 992 847 447 587 230 879 Store 2 699 378 928 658 374 44 149 845 917 707 519 222 877 Difference 245 84 56 300 83 101 -119 75 140 68 2 (Store 1 - Store 2) Send data to calculator Based on these data, can the owner conclude, at the 0.10 level of significance, that the mean daily sales of Store 1 exceeds that of Store 2?…

You are the marketing director for a company that manufactures bodybuilding supplements, and you are planning to run ads in Sports Illustrated and GQ Magazine. On the basis of readership data, you estimate that each ad in Sports Illustrated will be read by 600,000 people in your target group, while each ad in GQ will be read by 150,000. You would like your ads to be read by at least 12 million people in the target group, and you plan to place at least 6 ads in Sports Illustrated and at least 8 ads in GQ during the next year. Sports Illustrated quotes you $2000 per ad, while GQ quotes you $1000 per ad. How many ads should be placed in each magazine to satisfy your requirements at a minimum cost? Sports Illustrated ads GQ Magazine ads