00:01
Following is a solution to number 18, this looks at the 2005 honda accord average gas mileage and or miles per gallon.
00:09
And we sampled 40 2005 honda accords, and we found that the average or the sample mean for gas mileage or miles per gallon was 23 miles per gallon with a sample standard deviation of 1 .5.
00:23
And we're asked to construct and interpret a 95 % confidence interval based on that sample.
00:28
So we need to use a t interval because we don't know what the population standard deviation is.
00:33
We only know what the sample standard deviation is.
00:35
So we're given s, but we don't know what sigma is.
00:38
So since we only know s, we're going to use the t interval.
00:41
And i'm going to use the ti84 for this because it's pretty nice to use technology whenever you're available.
00:47
But you can use any sort of technology you want, or you can certainly use the formula.
00:50
But you should get the same answer.
00:52
If you go to stat on ti84 and you err over to tests, and it's this eighth option down here, interval...