Question

1. A random sample of size 49 is taken from a large population, measuring the time it takes to complete a driver’s license examination. The sample mean was found to be 47 minutes, and the sample standard deviation 5.89 minutes. Construct a 95% confidence interval around the sample mean

Answer 1

95% interval = mean ± 1.96 SEm

SEm = SD/√(n-1), but you can just use n

I hope this helps.

Answer 2

45.35 to 48.65

Answer 3

(z test interval) =45.35 to 48.65