Question

If a population has a variance of 25 and, from this population, we draw a sample of 100 with a sample mean of 5; what are the 95% confidence intervals? Include the lower bound _____ and upper bound _____ .

Answer 1

Solution :

Given that,

Sample size = n = 100

Z/2 = 1.96

Margin of error = E = Z/2* ( /n)

= 1.96 * (5 / 100)

Margin of error = E = 0.98

At 95% confidence interval estimate of the population mean is,

- E < < + E

5 - 0.98 < < 5 + 0.98

4.02 < < 5.98

The lower bound 4.02 and upper bound 5.98