00:01
So this asks us to calculate the probability of finding a random person with an iq between 95 and 118.
00:10
And to do that, we should have to use the z scores.
00:16
I already have the mean and the descent of deviation here.
00:21
So starting with the top score, which is 118, 118 minus 100, divided by 15.
00:31
So our value minus our mean.
00:33
Divided by our standard deviation.
00:36
And that gives us the z score of 1 .2.
00:40
And if we go on our chart, that z score will give us a value of 0 .88493.
00:52
And now to calculate the lower end, which is 95.
00:57
That's minus the mean of 100 divided by standard deviation.
01:01
That gives the value of negative 0 .3 repeating or just negative 0 .33.
01:12
And fill that up on the z chart, we get a value of 0 .307...