Statistics Question:
We intended to estimate the average driving time of a group of commuters from a previous study, we believe that the average time is 42 minutes with a standard deviation of 12 minutes. We want of 99 percent confidence interval to have a margin of error or no more than plus or minus 3 minutes. What is the smallest sample size we should consider?
Ok, So
n = 42 minutes
Stand. Deviation = 12
Confidence Interval = .99
Alpha = .005
Z-Score = +- 2.575 (I think)
and E = +-3
......Now what?
