Question

Based on interviews with 91 SARS patients, researchers found that the mean incubation period was 4.9 days, with a standard deviation of 15.4 days. Based on this information, construct a 95% confidence interval for the mean incubation period of the SARS virus. Interpret the interval. The lower bound is days. (Round to two decimal places as needed.) The upper bound is _______ (Round to two decimal places as needed)

Answer 1

Here sample size is sufficient large so we can use standard normal distribution to find CI

z value for 95% CI is 1.96 as P(-1.96<z<1.96)=0.95

So Margin of Error is

Hence CI is

The lower bound is 1.74. The upper bound is 8.06.