Question

The sampled population is normally distributed, with the given information. (Give your answers correct to two decimal places.) n = 18, x = 28.4, and σ = 5.7

(a) Find the 0.99 confidence interval for μ. ______    to ______

(b) Are the assumptions satisfied?

You may need to use the appropriate table in Appendix B to answer this question.

Answer 1

Ans.

(A).The sapmle is drawn from normal distribution with unkown mean $\mu$. Given that

n = 18, sample mean xbar = 28.4, SD $\sigma$ = 5.7

The 99% confidence interval for population mean $\mu$

= Xbar$\pm$t_critical*SD/sqrt(n)

= 28.4$\pm$2.90*5.7/sqrt(18)

=(24.50, 32.296)

(B). Yes stisfied the assumptions

And we use the probability table .