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Clinical literature reports that the duration of a typical cold is roughly 18 days. Researchers wanted to know if people tend to underestimate the duration of a typical cold, on average. They surveyed a random sample of 352 healthy adults in Georgia and asked them how long they think that a typical cold lasts. The researchers reported a 95% confidence interval of 6.9 to 8.2 days for the mean expected duration of typical cold. The researchers reported that the answers to this question were strongly right-skewed. The 95% confidence interval (6.9, 8.2) they obtained is Answer 1. :] likely appropriate because the answers of all healthy adults in Georgia are likely to be Normally distributed given that this is such a large population. 2. :] appropriate despite the skewed data because the sample size is large enough to rely on the robustness of the t procedures. 3. :1 not appropriate because the sample data are skewed. 4. :1 not appropriate because the answers of all healthy adults in Georgia are likely not Normally distributed. In a statistical test of hypotheses, we say the data are statistically significant at level a if Answer 1. C] alpha = 0.05. 2. C] alpha is small 3. C] P-value is less than or equal to alpha. 4. C] P-value is greater than alpha A drug company claims that fewer than 1% of pills that it produces and ships fail to retain full potency after 60 days of production. An inspector inspects a shipment of medications to determine the efficacy in terms of the proportion p in the shipment that failed to retain full potency after 60 days of production. To do so, she selects an SRS of 200 pills. Suppose that eight of the 200 pills have failed to retain their full potency. Please select all TRUE statement below. Answer 1.[: HO") H1:p .01 2-: Haip .01 H1: p alpha, we fail to reject Ho. 5. i: We reject the drug company's claim that fewer than 1% of pills that it produces and ships fail to retain full potency after 60 days of production. A drug company believes that at least half of all 13- to 17-year-olds with autism will repond better to a new drug therapy for autism. A random sample of 900 13- to 17-year-olds with autism found that 411 had responded better to this new drug therapy for autism. Let p be the proportion of all teens in this age range who respond better. The test statistic for the above hypothesis test for the proportion of 13- to 17-yearolds who respond better is... (Round your answer to the hundredths place.) Answer Identify the type I error. Choose the correct answer below. Answer 1. C] Reject the null hypothesis that the percentage of households with more than 1 pet is equal to 65% when that percentage is actually equal to 65%. 2. C] Reject the null hypothesis that the percentage of households with more than 1 pet is equal to 65% when that percentage is actually less than 65%. 3. C] Fail to reject the null hypothesis that the percentage of households with more than 1 pet is equal to 65% when that percentage is actually greater than 65%. 4. C] Fail to reject the null hypothesis that the percentage of households with more than 1 pet is less than 65% when that percentage is actually greater than 65%. Many states are carefully considering steps that would help them collect sales taxes on items purchased through the Internet. How many randomly selected sales transactions must be surveyed to determine the percentage that transpired over the Internet? Assume that we want to be 90% confident that the sample percentage is within two percentage points of the true population percentage for all sales transactions. (Round up to the next integer.)
