During a typical May in St. Louis, it rains once every 2.6 days. Using the exponential distribution, calculate the probability that no rain falls during the first week (7 days) in the month of May. (Hint: You can also think of this as the probability that the first rainy day happens after a week.) You may use any of these values, if you think it would be helpful:
Read DetailsUse this set-up for Problems 53-56: A Quinnipiac poll performed on January 28-February 1, 2021 asked Americans, “Are you willing to get a COVID-19 vaccine, or not?” 30% of respondents said they were not. You wonder whether this proportion has changed in the past few years, so you conduct a poll of 100 Americans and ask the same question. 25 people in your sample were unwilling to get the COVID-19 vaccine. Suppose you set . What hypotheses should you set-up to determine if the percentage has changed since the initial poll?
Read DetailsThe following contingency table provides a joint frequency distribution for a group of retired people by career and age at retirement. Round to 3 decimal places. Age at Retirement 50 – 55 56 – 60 61 – 65 Over 65 Total Attorney 9 41 90 49 189 College Professor 10 48 81 43 182 Administrative Assistant 21 45 63 49 178 Store Clerk 18 44 70 50 182 Total 58 178 304 191 731 Suppose one of these people is selected at random.Compute the probability that the person either retired between 56 – 60 or was an administrative
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