# Bsat 510 – Spring 2012

**Topics:**Variance, Standard deviation, Regression analysis

**Pages:**3 (686 words)

**Published:**March 18, 2012

Spring 2012

This assignment will count 50 points, per the syllabus.

Instructions:

• Show all work on your own paper. It is not necessary to turn in the original data as long as your answers are clearly labeled. • For exercises completed with SPSS, include the computer output that supports your answers. • Clearly label and circle (or highlight by hand) each answer. In other words, don’t just circle a value on the page without indentifying the particular part of a particular question to which it corresponds. For example, label as “#2a”. • Write your name at the top of each page that you turn in. • Staple your pages in the upper left-hand corner.

• Do not turn in computer work in electronic form; only hardcopy will be accepted. • An answer may span several pages, but do not turn in a table spanning more than one page.

1. A recent study by the American Automobile Dealers Association revealed the mean amount of profit per car sold for a sample of 20 dealers was $290, with a standard deviation of $125. a. Construct a 95% confidence interval for the true mean profit per car. b. Would it be reasonable to conclude that the mean profit is $225? Explain your answer. c. Is it possible that the mean profit is less than $200? Explain your answer. d. What assumption(s) need to be made to construct this interval? e. Write a brief summary of your findings/recommendations (3 or 4 sentences) for management.

2. A recent federal report indicated 27% of children ages 2-5 ate vegetables at least 5 times a week. a. How large a sample is necessary to estimate the true proportion of children ages 2-5 in the United States with 98% confidence with a margin of error of no more than 2%? b. If the cost of conducting the sample you found in part (a) was beyond your budget, how might you save money on the cost of sampling? Illustrate your answer with an example. c....

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