Question

a. A normally distributed population has a mean of 72 and a standard deviation of 22. Sample averages from samples of size 17 are collected. What would be the upper end of the centered interval that contains 95% of all possible sample averages?

Round to the nearest hundredth

b.

A normally distributed population has a mean of 54 and a standard deviation of 13. Sample averages from samples of size 24 are collected. What would be the lower end of the centered interval that contains 90% of all possible sample averages?

Round to the nearest hundredth

Answer 1

a)

72   2.120 ( 22 / 17 )

72   11.312

( 60.69 , 83.31 )

At 95 %, CI for Population mean is ( 60.69 , 83.31 )

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b)

54   1.714 ( 13 / 24 )

54   4.548

( 49.45 , 58.55 )

At 90 %, CI for Population mean is ( 49.45 , 58.55 )