One of the music industry’s most pressing questions is: Can paid download stores contend nose-to-nose with free peer-to-peer download services? Data gathered over the last 12 months show Apple’s iTunes was used by an average of 1.65 million households with a sample standard deviation of 0.56 million family units. Over the same 12 months WinMX was used by an average of 2.2 million families with a sample standard deviation of 0.30 million. Assume the population standard deviations are not the same. Using a significance level of 0.05, test the hypothesis of no difference in the mean number of households picking either variety of service to download songs.

The Damon family owns a large grape vineyard in western New York along Lake Erie. The grapevines must be sprayed at the beginning of the growing season to protect against various insects and diseases. Two new insecticides have just been marketed: Pernod 5 and Action. To test their effectiveness, three long rows were selected and sprayed with Pernod 5 , and three others were sprayed with Action. When the grapes ripened, 400 of the vines treated with Pernod 5 were checked for infestation. Likewise, a sample of 400 vines spray

A cell phone company offers two plans to its subscribers. At the time new subscribers sign up, they are asked to provide some demographic information. The mean yearly income for a sample of 40 subscribers to Plan A is $57,000 with a standard deviation of$9,200. This distribution is positively skewed; the actual coefficient of skewness is 2.11. For a sample of 30 subscribers to Plan B, the mean income is $61,000 with a standard deviation of$7,100. The distribution of Plan B subscribers is also positively skewed, but not as severely. The coefficient of skewness is 1.54. At the .05 significance level, is it reasonable to conclude the mean income of those selecting Plan B is larger? What is the p-value? Do the coefficients of skewness affect the results of the hypothesis test?Why?

If you use the Internet, have you ever paid to access or download music? This was one of the questions of interest in a recent Pew Internet and American Life Project Survey (Oct. 2010). Telephone interviews were conducted on a representative sample of 1,003 adults living in the United States. For this sample, 506 adults stated that they have paid to download music. a. Use the survey information to find a point estimate for the true proportion of U.S. adults who have paid to download music. b. Find an interval estimate for the proportion, part a. Use a 90% confidence interval. c. Give a practical interpretation of the interval, part b. Your answer should begin with "We are 90% confident ... " d. Explain the meaning of the phrase "90% confident."

Suppose you are a member of a research team and have become increasingly concerned about drug use by professional sports players as one of several factors affecting people's attitudes toward drug use in general. You set up a plan and conduct a survey on how people believe the American culture (television, movies, magazines, and popular music) influences illegal drug use. Your survey carries 2250 adults and adolescents from around the country. A consumer group petitions you for more information about your survey. Reply to the following questions about your survey.

1. What type of survey did you use (phone, mail, or interview)?

Presented below is selected information related to Martin Burke Inc. at year-end. All these accounts have debit balances.

Instructions

Identify which items should be classified as an intangible asset. For those items not classified as an intangible asset, indicate where they would be reported in the financial statements.

determine the order of the matrix. [1 6 -1 , 8 0 3 , 3 -9 9]

Find the indefinite integral. ∫ (sec² ti + 1/(1+t²) j) dt

A coffee manufacturer is interested in whether the mean daily consumption of regular-coffee drinkers is less than that of decaffeinated-coffee drinkers. Assume the population standard deviation for those drinking regular coffee is 1.20 cups per day and 1.36 cups per day for those drinking decaffeinated coffee. A random sample of 50 regular-coffee drinkers showed a mean of 4.35 cups per day. A sample of 40 decaffeinated-coffee drinkers showed a mean of 5.84 cups per day. Use the .01 significance level. Compute the p-value.

The null and alternate hypotheses are:

$$H_0:μ_1≤μ_2; H_1:μ_1>μ_2$$

A random sample of 20 items from the first population showed a mean of 100 and a standard deviation of 15. A sample of 16 items for the second population showed a mean of 94 and a standard deviation of 8. Use the .05 significant level.

A recent study focused on the number of times men and women who live alone buy take-out dinner in a month. Assume that the distributions follow the normal probability distribution and the population standard deviations are equal. The information is summarized below.

$$\begin{array}{|lcc|} \hline \text { Statistic } & \text { Men } & \text { Women } \\ \hline \text { Sample mean } & 24.51 & 22.69 \\ \text { Sample standard deviation } & 4.48 & 3.86 \\ \text { Sample size } & 35 & 40 \\ \hline \end{array}$$

At the .01 significance level, is there a difference in the mean number of times men and women order take-out dinners in a month? What is the p-value?

A computer manufacturer offers a help line that purchasers can call for help 24 hours a day, 7 days a week. Clearing these calls for help in a timely fashion is important to the company’s image. After telling the caller that resolution of the problem is important, the caller is asked whether the issue is software or hardware related. The mean time it takes a technician to resolve a software issue is 18 minutes with a standard deviation of 4.2 minutes. This information was obtained from a sample of 35 monitored calls. For a study of 45 hardware issues, the mean time for the technician to resolve the problem was 15.5 minutes with a standard deviation of 3.9 minutes. This information was also obtained from monitored calls. At the .05 significance level, does it take longer to resolve software issues? What is the p-value?

The owner of Bun ‘N’ Run Hamburgers wishes to compare the sales per day at two locations. The mean number sold for 10 randomly selected days at the Northside site was 83.55, and the standard deviation was 10.50. For a random sample of 12 days at the Southside location, the mean number sold was 78.80 and the standard deviation was 14.25. At the .05 significance level, is there a difference in the mean number of hamburgers sold at the two locations? What is the p-value?

Ms. Lisa Monnin is the budget director for Nexus Media Inc. She would like to compare the daily travel expenses for the sales staff and the audit staff. She collected the following sample information.

$$\begin{array}{|llllllll|} \hline \text{ Sales (\$) } & 131 & 135 & 146 & 165 & 136 & 142 & \\ \text{ Audit (\$) } & 130 & 102 & 129 & 143 & 149 & 120 & 139 \\ \hline \end{array}$$

Can she draw the conclusion that the mean daily expenses for the audit personnel are lower than for the sales staff at the.10 significance level? What does p-value mean?