00:02
First, we'll draw a picture.
00:10
We want to find the area to the left of the z score 3 .0.
00:13
The key to solving these problems is remembering that the standard normal table gives the area to the left of the specified z score.
00:21
So for us, we're going to start by looking for 3 .0, and we line up with the correct column, which is the first column in this case, and we get 0 .99 -865.
00:39
For b, we want the z score.
00:48
Negative 1 .55 and we want the area for everything under the curve for z values greater than negative 1 .55.
01:02
So we're going to again use our said table, but this time we're going to have to calculate the area to the left first since that's what our table gives us.
01:14
So we're going to look for negative 1 .55 on our table.
01:20
So we know our answer will be somewhere in this row and we just pick the column that corresponds with negative 1 .55, which is this one right here.
01:28
So we have 06 -057.
01:34
And we know that the red area is given by 1 minus the green area, or 1 minus 0 .06 -57.
01:44
And if we type that into our calculator, we get 0 .933 -943 for our c.
02:02
We want the area less than negative 0 .75...