00:01
There is a normal distribution here and the mean is given as 100 and the standard deviation that is 15.
00:06
Let's say x is normally distributed that is 115.
00:11
So in the graph, so it says the probability of x is greater than, let's say this is x1 value, which has the probability of 0 .6.
00:23
So in this case, we know the probability.
00:26
So we have to just find the standard this score by using the inverse number.
00:30
Norm calculation.
00:32
So for the ti 84, just press the button second and the distribution, you will see the inverse norm.
00:38
So for the standard z squared, the mee is zero standard division is one, and the given area is 0 .6.
00:44
Let's get the z value here, which is, so we got the z value here is negative 0 .233.
00:52
So we can also express this area as if for the ti, which is the probability of x is less than x1, which is equal to 1 minus 0 .6, which is 0 .4.
01:04
So we can find the same z value as using this one, v is zero, standard division is 1, and the ria is 0 .4...