Question

Assuming the population has an approximate normal distribution, if a sample size n=18n=18 has a sample mean ¯x=44x¯=44 with a sample standard deviation s=8s=8, find the margin of error at a 95% confidence level. Round the answer to two decimal places.

Answer 1

3.7

plus or minus 3.7

Explanation:

z alpha/2=1.96

z alpha/2 multiply by( standard deviation/square root of sample)

standard deviation s=8

sample n=18

=3.7