00:01
Hey there, welcome to numerade.
00:04
We are asked to find the value of the test statistic, where we know the speed limit on a portion of i -95 is 62.
00:14
So therefore, this value here, 62, represents our population mean, and we have our sample size here given as 40 cards.
00:30
So knowing this, we were asked to find the test.
00:33
Stat, but before we find it, we have to find our sample mean and sample standard deviation.
00:40
So for our sample mean, we have the sum of x divided by our sample size 40, given us a mean of exactly 66.
00:51
For our sample standard deviation, we're going to take the square root of, our sum of x minus the mean 40 and squared, divided by our sample size 40 minus 1.
01:06
This will give us a standard deviation of around 3 .74.
01:12
All right, so knowing this here, what we have for our test stats equation is t equals our sample mean minus our population mean divided by our standard deviation divided by the square root of n.
01:42
So let's go ahead and plug in our values...