A sample of 94 WCC students found mean age 24.7 years old with standard deviation 7.9...

A sample of 94 WCC students found mean age 24.7 years old with standard deviation 7.9 years old.

(a) Make a 90% confidence interval for the mean age of all WCC students. Interpret the interval.

(b) Redo (a) if instead of 94 students, only 13 students had been sampled. Do not interpret the interval.

Expert Solution

Solution:- Given that n = 94, X = 24.7, s = 7.9

(a) 90% Confidence interval for the mean age is (23.35,26.05)

interpretation:
if repeated samples of same size were taken and the 90% confidence interval was computed for each smple, 90% of the intervals would contain mean. we are 90% certain that the interval (23.35,26.05) contains the population mean age.

(b) for n = 13,

90% Confidence interval for the mean age is (20.80,28.61)

orchestra answered 1 year ago

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