Question

A random sample of 900 members is found to have a mean of 4.45 CM can it be reasonably regarded as a sample from a large population whose mean is 5 cm and variance is 4 cm square obtain the 95% confidence limit for the mean in the population

Answer 1

$95\%CI=(\bar x-t_{0.025,n-1}\frac{\sigma}{\sqrt{n}}, \bar x+t_{0.025,n-1}\frac{\sigma}{\sqrt{n}})=$

$=(4.45-1.963\frac{2}{\sqrt{900}}, 4.45+1.963\frac{2}{\sqrt{900}})=$

$=(4.319, 4.581).$