Question

To estimate the average annual expenses of students on books and class materials a sample of size 36 is taken. the sample mean is $850 and the sample standard deviation is $54. a 99 percent confidence interval for the population mean is

Answer 1

The 99 percent confidence interval for the population mean is found from:

`\bar{x}-2.576(s)/( √(n) )\ \textless \ \mu\ \textless \ \bar{x}+2.576(s)/( √(n) )`

`850-2.576(54)/( √(36) )\ \textless \ \mu\ \textless \ 850+2.576(54)/( √(36) )`
The answer is:

`826.82\ \textless \ \mu\ \textless \ 873.18`