posted by Jessica on .
Build a 95% confidence interval for the mean of the population from the given sample data. Assume that the population has a normal distribution.
16.4, 15.7, 16.2, 15.8 17.1
15.8, 15.9, 16.0, 16.4 15.0
95% interval = mean ± 1.96 SEm
SEm = SD/√(n-1)
Find the mean first = sum of scores/number of scores
Subtract each of the scores from the mean and square each difference. Find the sum of these squares. Divide that by the number of scores to get variance.
Standard deviation = square root of variance