Question

A random sample of 90 observations produced a mean that = 25.9 and a standard deviation s =2.4
(a)Find a 95% confidence interval for u
(b)Find a 90% confidence interval for u
(c)Find a 99% confidence interval for u
(Use integers or decimals for any number in the expression. Round to two decimal places

Answer 1

a. 25.4 -+ 1.96 * 2.4 /sqrt((90))

b. 25.4 -+ 1.645 * 2.4 /sqrt((90))

c. 25.4 -+ 2.575 * 2.4 /sqrt((90))