00:01
Toad here is a normal distribution and we're getting with a z curve so we know then right away that the mean is zero and the standard deviation is 1.
00:13
So 1 and 0.
00:19
I want to be in the top 12 % for the first one here, which means i'm going to be somewhere over here on the right.
00:29
I want to find z1 where this area here.
00:35
Is 12 % or in decimal form .12.
00:43
Well what that means is the area below z1 has to be 1 minus 0 .12 so 0 .88.
00:53
The area under a z curve or at any normal curve is always 1.
01:00
So to work out z1 use a calculator.
01:05
The ti 84 plus is the best one to use.
01:08
And the function you want is called inverse norm.
01:15
And that next time here, inverse norm.
01:21
To get that, press second, the blue button, second, followed by vars, v -a -r -s, on the right, just below the arrow key.
01:31
That brings up the menu for distributions...