00:01
Okay, let's draw the z curve first.
00:04
And this has symmetry about the y axis.
00:08
We know the sd is 1 and the mean is 0.
00:13
So what i want, first of all, the chance that a z score is above negative 1 .46.
00:21
So over here somewhere, negative 1 .46.
00:25
I want to find this area under the normal curve.
00:29
The entire area is always one.
00:32
So that area represents the chance you're above that number.
00:37
So press one then, p of z greater than negative 1 .42 will be.
00:49
And here we need to use a function normal cdf, normal cdf, which you can find on the ti84 plus calculator.
01:06
Second followed by vars v -a -r -s that brings up the menu for distributions.
01:15
Vars you'll find on the right just below the arrow keys and on that menu you will see normal cdf, second one down so choose that with the arrow key and press enter and it will say lower upper mean sd or lower is negative 1 .42 upper pick some random high number, like 100, that's more than enough.
01:46
10 will work actually, so 100.
01:50
And then 0 -1.
01:52
So 4 -number input.
01:54
I have a lower 1, negative 1 .42.
01:58
Upper, some random very high number.
02:01
That's way over here, for example.
02:04
So i chose 100.
02:06
Mean, mu, 0, sd1.
02:09
Paste and enter and the answer is 0 .92219 so 0 .9222 to 4 decimal places.
02:25
No mention here or accuracy if you find then that's the first one.
02:34
Second one says p of z less than 0 minus 0 .38.
02:50
Okay, so again here's the z score.
02:57
What i want over here is minus 0 .38.
03:04
And i want the area below minus 0 .38...