HELP: math STATISTICS question.....

[krunchykrome]

I need to find a 90% confidence interval for a population mean.
My sample is 62.
My textbook gives an equation for a small random sample confidence interval, less than or equal to 30.

This is what it says:

_ _
x - E < Population Mean < x + E

If that is the confidence interval for a small sample, less than 30....how do I find one for a sample of 62?

 

[AbsoluteParadigm]

Sample size effects the margin of error. Check the formula for the margin of error and see if sample size is involved. If not, then don't worry about it. If it is then just plug 62 into the formula for the margin of error. Margin of error = E in your equation.

 

[krunchykrome]

The margin of error (E)=

"t-value" x(times) standard deviation/ Square root of "n"

where "n" equals the sample size.

 

[AbsoluteParadigm]

Then plug 62 into the formula for n and compute a new margin of error.