C look high leverage and outlier observations what do

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c) Look high leverage and outlier observations. What do you find? d) Select the most suspicious observation from your results in c) and determine how influential the observation is. 2. Publishers of a weekly magazine believe a large proportion of their subscribers invest in the stock market. They would like to use this information to persuade brokerage firms to advertise in the magazine. The publisher sends each of the 150,000 subscribers a questionnaire about stock investments. A total of 6500 questionnaires are returned, and of these 5997 subscribers respond that they currently have stock market investments. a) Use this information to estimate the proportion of subscribers who currently have stock market investments and place a bound on the error of estimation. b) Should the brokerage firm consider the estimate in a) reliable? Explain. c) Suppose instead the publisher decides to personally interview a random sample of their subscribers. In order to estimate, with approximately 95% confidence, the true proportion investing in the stock market with a bound on the error of estimation of width 0.05, how many of the 150,000 subscribers should be included in the sample? d) Ignoring the concern in part b), suppose the publisher also wants to estimate the average stock market portfolio value. The results from the questionnaire give the sample average value as $116,500 and the sample standard deviation of $53,870. Determine a 99% confidence interval for
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