A simple random sample of size n is drawn from a population that is normally distributed. The sample mean, x overbar, is found to be 115, and the sample standard deviation, s, is found to be 10.

(a) Construct a 90% confidence interval about mu if the sample size, n, is 15.

(b) Construct a 90% confidence interval about mu if the sample size, n, is 29.

(c) Construct a 95% confidence interval about mu if the sample size, n, is 15.

(d) Could we have computed the confidence intervals in parts (a)-(c) if the population had not been normally distributed?

LOADING...

Click the icon to view the table of areas under the t-distribution.

(a) Construct a 90% confidence interval about mu if the sample size, n, is 15.

Lower bound: nothing;

Upper bound: nothing

(Use ascending order. Round to one decimal place as needed.)