00:01
So we're looking at a normal distribution that has a mean of 130 and a standard deviation of 26 .2.
00:10
We want to know the z -scores that correspond to the following test scores.
00:15
So we're going to do it for x equals 111, 134, 166, and 156.
00:23
So let's look and then what that's we're going to say our data point, which is 111 minus 130 over our standard deviation.
00:33
So we're going to do that for each one of these 166 minus 130 over 26 .2, 156 minus 130 over 26 .2.
00:47
Let's go ahead and get all of those 111 minus 130 and divide by 26 .2.
00:54
We're going to get negative .73 and then for the next one, we're going to get .15.
01:03
For the next one, we're going to get 1 .37.
01:11
And for the next one, we're going to get .99.
01:18
Now for the next one, if we have z -scores of 250 and negative 250, then what were the test scores? so i'm going to go 250 and negative, that's 2 .5.
01:29
I made it look wrong...