00:01
Alright, so we have shoe sizes normally distributed with a mean of 15, this is an deviation of 4.
00:05
And we want to find the probability that the shoe sizes, with a percentage of shoes between 15 and 16 inches.
00:17
First what i want to do is find the z score for these shoe sizes.
00:21
So it's going to be 15 minus 16, 15 rather, over this standard deviation of 4 for the left -hand side.
00:36
And on the right -hand side, it's going to be 16 minus 15 over 4.
00:42
So that's going to give us the probability that z is between 0 and 0 .25.
00:58
And this is probability that z is less than 0 .25, minus probability z is less than 0 .5.
01:12
And we get 0 .597, minus 0 .5, which is 0 .0987.
01:21
And if we think that a percentage, it's 9 .87%.
01:25
Rounded to 1 decimal goes to 9 .9%...