In a recent study of 51 eighth graders the mean number of ho

In a recent study of 51 eighth graders, the mean number of hours per week that they watched television 21.9. Assuming ? = 5.8 hours, construct a 99% confidence interval for the population mean. Interpret the meaning of this interval.

Please show equations and explain

Solution

Given a=1-0.99=0.01, Z(0.005) = 2.58 (from standard normal table)

So the lower bound is

xbar - Z*s/vn =21.9 -2.58*5.8/sqrt(51) = 19.80462

So the upper bound is

xbar + Z*s/vn=21.9 +2.58*5.8/sqrt(51) =23.99538

We have 99% confident that the population mean will be within this interval.