00:01
So the nice thing about the normal distribution is that everything is symmetric around zero.
00:07
So all of our z scores live along this number line down here.
00:12
And then we have the area under the curve is all of our probabilities, and all the probabilities have to add up to 100%.
00:19
So the area under the curve adds up to 1.
00:22
So if we're looking for z values, and we want the area, the amount in between them, to be 12 % or 0 .12, we're looking for here's a negative z value and then a positive z value here.
00:39
The negative because it's the left of zero, the positive because it's to the right of zero.
00:44
Now, since everything has to add up to 100%, we know that the rest of the area has to add up to the 0 .88 because that's 100 % minus the 12 % we already have because the 12 % is going to be this area in between in here.
01:07
So each of these guys is going to be 0 .44 and this is 0 .44...