Chapter 9: Problem 55
Define the power of a statistical test. As the alternative value of \(\mu\) gets farther from \(\mu_{0}\), how is the power affected?
/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none}
Learning Materials
Features
Discover
Chapter 9: Problem 55
Define the power of a statistical test. As the alternative value of \(\mu\) gets farther from \(\mu_{0}\), how is the power affected?
All the tools & learning materials you need for study success - in one app.
Get started for free
Early Detection of Breast Cancer Of those women who are diagnosed to have early-stage breast cancer, one-third eventually die of the disease. Suppose a community public health department instituted a screening program to provide for the early detection of breast cancer and to increase the survival rate \(p\) of those diagnosed to have the disease. A random sample of 200 women was selected from among those who were periodically screened by the program and who were diagnosed to have the disease. Let \(x\) represent the number of those in the sample who survive the disease a. If you wish to detect whether the community screening program has been effective, state the null hypothesis that should be tested. b. State the alternative hypothesis. c. If 164 women in the sample of 200 survive the disease, can you conclude that the community screening program was effective? Test using \(\alpha=.05\) and explain the practical conclusions from your test. d. Find the \(p\) -value for the test and interpret it.
Colored Contacts Refer to Exercise \(9.37 .\) Contact lenses, worn by about 26 million Americans, come in many styles and colors. Most Americans wear soft lenses, with the most popular colors being the blue varieties \((25 \%),\) followed by greens \((24 \%),\) and then hazel or brown. A random sample of 80 tinted contact lens wearers was checked for the color of their lenses. Of these people, 22 wore blue lenses and only 15 wore green lenses. a. Do the sample data provide sufficient evidence to indicate that the proportion of tinted contact lens wearers who wear blue lenses is different from \(25 \% ?\) Use \(\alpha=.05 .\) b. Do the sample data provide sufficient evidence to indicate that the proportion of tinted contact lens wearers who wear green lenses is different from \(24 \% ?\) Use \(\alpha=.05\) c. Is there any reason to conduct a one-tailed test for either part a or b? Explain.
Independent random samples of 280 and 350 observations were selected from binomial populations 1 and 2 , respectively. Sample 1 had 132 successes, and sample 2 had 178 successes. Do the data present sufficient evidence to indicate that the proportion of successes in population 1 is smaller than the proportion in population \(2 ?\) Use one of the two methods of testing presented in this section, and explain your conclusions.
Hotel Costs In Exercise \(8.18,\) we explored the average cost of lodging at three different hotel chains. We randomly select 50 billing statements from the computer databases of the Marriott, Radisson, and Wyndham hotel chains, and record the nightly room rates. A portion of the sample data is shown in the table $$\begin{array}{lcc} & \text { Marriott } & \text { Radisson } \\\\\hline \text { Sample Average } & \$ 170 & \$ 145 \\\\\text { Sample Standard Deviation } & 17.5 & 10\end{array}$$ a. Before looking at the data, would you have any preconceived idea about the direction of the difference between the average room rates for these two hotels? If not, what null and alternative hypotheses should you test? b. Use the critical value approach to determine if there is a significant difference in the average room rates for the Marriott and the Radisson hotel chains, Use \(\alpha=.01\) c. Find the \(p\) -value for this test. Does this \(p\) -value confirm the results of part b?
Put on the Brakes The braking ability was compared for two 2012 automobile models. Random samples of 64 automobiles were tested for each type. The recorded measurement was the distance (in feet) required to stop when the brakes were applied at 50 miles per hour. These are the computed sample means and variances: Do the data provide sufficient evidence to indicate a difference between the mean stopping distances for the two models?
What do you think about this solution?
We value your feedback to improve our textbook solutions.