10.1 EXERCISES 532 CHAPTER 10 Chi-Square Tests and the F-Distribution For Extra Help: MyLab® Statistics Building Basic Skills and Vocabulary 1. What is a multinomial experiment? 2. What conditions are necessary to use the chi-square goodness-of-fit test? Finding Expected Frequencies In Exercises 3–6, find the expected frequency for the values of n and pi. 3. n = 150, pi = 0.3 4. n = 500, pi = 0.9 5. n = 230, pi = 0.25 6. n = 415, pi = 0.08 Using and Interpreting Concepts Performing a Chi-Square Goodness-of-Fit Test In Exercises 7–16, (a) identify the claim and state H0 and Ha, (b) find the critical value and identify the rejection region, (c) find the chi-square test statistic, (d) decide whether to reject or fail to reject the null hypothesis, and (e) interpret the decision in the context of the original claim. 7. Ages of Moviegoers A researcher claims that the ages of people who go to the movies at least once a year are distributed as shown in the figure. You randomly select 1000 people who went to the movies at least once in 2020 and record the age of each. The table shows the results. At a = 0.10, test the researcher’s claim. (Adapted from Motion Picture Association of America) How old are moviegoers? 15% 11% 13% 11% 50+ 25% 2–11 12–17 18–24 25–39 40–49 Age of those who go to movies at least once a year 25% Survey results Age Frequency, f 2–11 146 12–17 116 18–24 131 25–39 232 40–49 117 50+ 258 8. Coffee A researcher claims that the numbers of cups of coffee U.S. adults drink per day are distributed as shown in the figure. You randomly select 1600 U.S. adults and ask them how many cups of coffee they drink per day. The table shows the results. At a = 0.05, test the researcher’s claim. (Adapted from Gallup) How many cups-o-joe do you drink per day? About 64% of Americans drink at least 1 cup per day. 1 cup 26% 0 cups 36% 2 cups 19% 3 cups 8% 4 or more cups 11% How much they drink: Survey results Response Frequency, f 0 cups 570 1 cup 432 2 cups 282 3 cups 152 4 or more cups 164
RkJQdWJsaXNoZXIy NjM5ODQ=