Anna Audler Stats 10: Section 3A UID: 304295761 TA: Luis Sosa Homework #6 7.1: Parameter is a measure of the whole population; a statistic is a measure of a sample 7.3: a.) x-bar is statistic, μ is parameter b.) x-bar 7.6: We would still not be able to make inferences since we have the population (in this case the men’s basketball team), but not a sample from the population. 7.13: Marco took a convenience sample, so the students may not be representative of the population and therefore the proposition won’t pass. 7.15: The population in this case is all readers of the Time magazine. The problem is the Time survey uses a voluntary response poll. Possibly the only people who bothered to answer the survey are upset at the United States in this case and may have shown bias 7.16: In doing so, the polling agencies are able to randomize the sample of adults that they speak to over the phone by giving equal chances to whether the female or male adult will be picked. 7.19: The sample would not be random, as the only group that would be picked for the sample would most likely be university students (convenience sample) 7.41: a.) 0.5 b.) 0.5 c.) 0.103 d.)lower as the probability of guessing correctly on each question decreases when there are more options, in this case four. 7.63: a.) 74/1438 = 5.15% b.) 95%; CI (0.040, 0.063) c.) 5% is plausible because it’s within the confidence interval7.64: a.) 22.45% b.) 95%; CI (0.213, 0.243) c.) it is not plausible as it is far out from the interval. 8.5: ii. p=0.50 8.6: iv. p=1/6 8.11: It does not; 0.05 8.13: z = 0.89 8.16: The p-value tells us that if the true proportion of those who were simply guessing is 0.50 then there is only a 0.079 probability that someone would get a sample proportion of 0.60 or smaller with sample size of 50 questions. 8.23: H0: Death rate is 9.9%; HA: Death rate is less than 9.9% 8.27: H0: p = 0.52: Ha: p does not equal 0.52 Sample size large (1011x0.48 = about 485), sampling random, and population large pn = 0.4896; SE = 0.01571; z = -1.93; p-value = 0.053; Fail to reject H0; Choose conclusion i. 8.32: p^ = 18/30 = 0.6 (0.6 - .50)/sqrt[(0.5 x 0.5)/30] = 1.09 p-value = 1 - 0.8621 = 0.1379 8.45: H0: pV = pp (pV is the population proportion who could use Vioxx and pp is the population proportion who could use the placebo); HA: pV>pp; z = 2.46; p-value = 0.007; reject H0; choose ii but we can’t generalize because this is a random assignment, not a random
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