A sample of 51 night-school students' ages is obtained in order to estimate the mean age of night-school students. x = 26 years. The population variance is 19.

Question

(a) Give a point estimate for μ. (Give your answer correct to one decimal place.)

(b) Find the 95% confidence interval for μ. (Give your answer correct to two decimal places.)
Lower Limit
Upper Limit

(c) Find the 99% confidence interval for μ. (Give your answer correct to two decimal places.)
Lower Limit
Upper Limit

Answer 1

95% = mean ± 1.96 SEm

99% = mean ± 2.575 SEm

SEm = SD/√n

SD^2 = variance

I'll let you do the calculations.