Question

for a random sample of 36 items and a sample mean of 211,compute a 95% confidence interval for if population standard deviation is 23

Answer 1

The z value is; 1.96

The interval will be calculated by the following formula;

$mean \pm \frac{z×sd}{\sqrt{N}}$

$211 \pm \frac{1.96×23}{\sqrt{36}}$

Evaluating we get an interval of:

203.49 to 218.51