Question

Take a sample of 40 ACT scores with a sample mean of 21 and a known...

Take a sample of 40 ACT scores with a sample mean of 21 and a known population standard deviation of 5.

Construct a 95% Confidence Interval for the mean ACT score.

Homework Answers

Answer #1

n = 40

SE = /

= 5/

= 0.7906

= 0.05

From Table, critical values of Z = 1.96

Confidence Interval:

21 (1.96 X 0.7906)

= 21 1.5495

= ( 19.4505 ,22.5495)

Confidence Interval:

19.4505 <   < 22.5495

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