00:01
All right, so i see that you need help with this question, and it says researchers are interested in the average time it takes people to drive to work.
00:07
Twenty randomly selected people were surveyed, and the data is shown to the right.
00:12
So a, determine the mean and the standard deviation of this sample data.
00:18
So first of all, there are 20 numbers, and the mean of these numbers is 29 .55.
00:29
The standard deviation of these values is 9 .48, and it says using these, using this sample, determine the margin of error to estimate the average drive time to work based on a 90 % desired level of confidence.
00:50
So before you can calculate the margin of error, you have to calculate your t score.
00:56
So you're going to do t, for your t score, you're going to do 1 minus 0 .9, and that's 0 .01.
01:05
Then you're, no, that's 0 .1, not 0 .01...