Author Archives: Anonymous
An economist wants to estimate the mean income for the first…
An economist wants to estimate the mean income for the first year of work for college graduates who had the grit to do well in statistics. Assuming she wants to be 99% confident that her estimate is within $500 of the true population mean income, what sample size is she going to need? Hint: a previous study found that the standard deviation of first year income was $12,000.Need sample size = [size] (be sure to round up to the nearest whole number)
Read Details10. A powerful and prominent interest group who got its fir…
10. A powerful and prominent interest group who got its first female president ever in the person of Liz Shuler is: A. National Education Association B. American Association for Retired Persons C. American Federation of Labor and Congress of Industrial Organizations (AFL-CIO) D. National Governors Association
Read DetailsA research firm wishes to conduct a study of voters in Washi…
A research firm wishes to conduct a study of voters in Washington County who favor a certain state initiative. Previous studies reveal that 55% of voters favor the initiative. Researchers wish to conduct another survey in which the margin of error is no more than 2.0%. Assuming a 98% confidence level, answer the following questions.What is the positive critical value alpha/2? [critval] (round to 3 decimal places)What is the sample size needed to insure the desired margin of error = [n] (rounded up to the nearest whole number)
Read DetailsA bookstore claims that students spend, on average, exactly…
A bookstore claims that students spend, on average, exactly $500 on textbooks per semester. A random sample of n=100 students has x-bar=$512 and s=$60. Use alpha=0.05. Give the final conclusion about the claim: supported or not supported. (answer with “supported” or “not supported”)
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