00:01
So for this problem, let's begin by considering our standard normal distribution.
00:05
You know it's going to look something like this, vaguely, pretend that that was perfectly symmetric.
00:11
We know that the mean value is at zero, the middle is at zero.
00:18
We know that the points of inflection are at plus and minus one, and we're told that a vertical line is drawn through a normal distribution at z -equals negative 1, which separates the distribution into two sections, referred to as the body and the tail.
00:35
So we can see that the area to the left of negative one is going to be the tail.
00:40
The area to the right of negative one is going to be the body.
00:45
And we're asked what proportion of the distribution is in the body.
00:49
So that is the proportion of the standard normal distribution to the right of negative one, which in turn would be the same thing as one minus the proportion to the left of negative one...