8.10 An economic survey is designed to estimate the average amount spent on utilities for households in a city. Because no list of households is available, cluster sampling is used, with divisions (wards) forming the clusters. A simple random sample of 20 wards is se- lected from the 60 wards of the city. Interviewers then obtain the cost of utilities from each household within the sampled wards; the total costs are shown in the accompanying table. Estimate the average amount a household in the city spends on utilities and place a bound on the error of estimation. Total amount Total amount spent on utilities spent on utilities Sampled Number of Number of Sampled ward ward households (dollars) households (dollars) 1 55 2210 11 73 2930 2 60 2390 12 64 2470 3 63 2430 13 69 2830 4 58 2380 14 58 2370 5 71 2760 15 63 2390 78 3110 16 75 2870 7 69 2780 17 78 3210 8. 58 2370 18 51 2430 9. 52 1990 19 67 2730 10 71 2810 20 70 2880

The International League of Triple-A minor league baseball consists of 14 teams organized into three divisions: North, South, and West. The data showing the average attendance for the 14 teams in the International League are contained in the Excel Online file below. Also shown are the teams’ records; W denotes the number of games won, L denotes the number of games lost, and PCT is the proportion of games played that were won. Construct a spreadsheet to answer the following questions.   Team Name Division W L PCT Attendance Buffalo Bisons North 66 77 0.462 8791 Lehigh Valley IronPigs North 55 89 0.382 8454 Pawtucket Red Sox North 85 58 0.594 9080 Rochester Red Wings North 79 70 0.53 6909 Scranton-Wilkes Barre Yankees North 88 56 0.611 7164 Syracuse Chiefs North 69 77 0.473 5749 Charlotte Knights South 68 78 0.466 4545 Durham Bulls South 74 70 0.514 7020 Norfolk Tides South 64 78 0.451 6269 Richmond Braves South 63 79 0.444 4449 Columbus Clippers West 69 73 0.486…

An agent for a residential real estate company in a large city has the business objective of developing more accurate estimates of the monthly rental cost for apartments. Toward that goal, the agent would like to use the size of an apartment, as defined by square footage to predict the monthly rental cost. The agent selects a sample of 25 apartments in a particular residential neighborhood and collects the following data:   Size (square feet) Rent ($) 850 1950 1450 2600 1085 2200 1232 2500 718 1950 1485 2700 1136 2650 726 1935 700 1875 956 2150 1100 2400 1285 2650 1985 3300 1369 2800 1175 2400 1225 2450 1245 2100 1259 2700 1150 2200 896 2150 1361 2600 1040 2650 755 2200 1000 1800 1200 2750     (a) Determine the coefficient of determination, r2, and interpret its meaning. (b) Determine the standard error of the estimate (Syx).…

C6. How many hours per week do you spend on e-mail? Data are presented here for a GSS sample of 99 men and women, who each reported the number of hours they spent per week on e-mail. a. Compute the cumulative frequency and cumulative percentage distribution for the data. b. What proportion of the sample spent 3 hours or less per week on e-mail? C. What proportion of the sample spent 6 or more hours per week on e-mail? d. Construct a graph that best displays these data. Explain why the graph you selected is appropriate for these data. E-mail Hours per Week Frequency 19 20 1 13 2 2 4 6. 6. 2 8. 1 6. 23 10 or more 7.

Consumer Reports rated automobile insurance companies and gave annual premiums for top-rated companies in several states. The figure below shows premiums for urban customers (married couple with one 17-year-old son) in three states. The box plots were all drawn using the same scale on a TI-8- Texas Pennsylvania California (a) Which state has the lowest premium? the highest? O lowest, California; highest, Texas O lowest, Texas; highest, Pennsylvania O lowest, Pennsylvania; highest, California lowest, California; highest, Pennsylvania

The estimated labor cost associated with a particular proposal is based on the number of plantings of trees, shrubs, and so on to be used for the project. For cost-estimating purposes, managers use two hours of labor time for the planting of a medium-sized tree. Actual times from a sample of 10 plantings during the past month follow (times in hours). 1.6 1.5 2.6 2.3 2.5 2.3 2.6 3.0 1.3 2.3 What is the test statistic? (Round your answer to three decimal places.) What is the p-value? (Round your answer to four decimal places.) p-value =