Question

Estimate the population mean by finding a 80% confidence interval given a sample of size 54, with a mean of 36.1 and a standard deviation of 10.8.

Preliminary:

1. Is it safe to assume that n≤0.05n≤0.05 of all subjects in the population?
   • Yes
   • No
   
   
2. Is n≥30n≥30?
   • Yes
   • No

Confidence Interval: What is the 80% confidence interval to estimate the population mean? Enter your answer as an open-interval (i.e., parentheses) accurate to one decimal place.

80% C.I. =

Answer 1

Solution:

Yes, it will be safe to assume that the sample size is less than the 5% of all subjects in the population.
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n = 54 ≥ 30
Yes
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80% C.I. = (34.2, 37.9)