Answer to Question #168665 in Statistics and Probability for ssqde

Question

determine a 95% confidence interval for the mean of a normal population with variance 6.25

Answer 1

Standart deviation S = $\sqrt{6.25}$ = 2.5

From the standard normal (Z-) distribution, z*-value of confidence level 95% is 1.96

$\bar{x} ±1.96\frac{\sigma}{\sqrt{n}}$