Question

5) Suppose that simple random samples of college freshman are selected from two universities, 25 students from school A and 20 students from school B. On a standardized test, the sample from school A has an average score of 1010 with a standard deviation of 100. The sample from school B has an average score of 990 with a standard deviation of 90.

a) What is the 90% confidence interval for the difference in test scores at the two schools? Use your calculator.

b) Interpret the confidence interval.

c) What is the margin of error?

Answer #1

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Suppose that random samples of college freshman are selected
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from school B. On a standardized test:
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standard deviation of 100.
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