Question

Based on interviews with 90 SARS​ patients, researchers found that the mean incubation period was 5 ​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 ____.

The upper bound is ____.

We are 95% confident that population mean is between ____ and ____.

Answer 1

Confidence interval, CI = Z*

For 95% confidence level, Z* = 1.96

= 5 days

s = 15.4 days

n = 90

CI = 5 1.96 x

= 5 3.182

= (1.818, 8.182)

The lower bound is 1.818

The upper bound is 8.182

We are 95% confident that population mean is between 1.818 and 8.182