# Statistics

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A simple random sample of 120 SAT scores ahs a mean of 1540. Assume that SAT scores have a population standard deviation of 333.

a) Construct a 95% conf. interval estimate of the mean SAT score.

b) Is a 99% conf. interval estimate of the mean SAT score wider than the 95% conf. interval estimate you got from part (a)? Why?

• Statistics -

95% = mean ± 1.96 SEm

SEm = SD/√n

99% = mean ± 2.575 SEm

This should allow you to answer the questions.

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