00:01
So to calculate this probability, we need to calculate two different z scores, one for 172 and one for 192.
00:07
So to do this, we use this equation.
00:11
So we have x of 172 minus our population mean, which is 174, divided by the standard deviation of 20.
00:25
And you calculate this to get a z score of negative 0 .1.
00:32
Then to get our other z score, we repeat the same process.
00:36
But instead of using the 172, we use the 192.
00:39
And then for this z score, you should get positive 0 .9.
00:46
Now these z scores are numbers that fall on the normal distribution, and this is going to be a z score of 0 would fall right down the middle.
01:00
And we're looking for the probability that x is between these two numbers, so between our two z scores...