00:01
This one, all of them are normally distributed, and you have groups of six for each question.
00:12
I'm only going to do two, you do the other four.
00:16
So in eight part a, you want to convert to the z score, or the mean was 60, and the standard deviation was 12.
00:28
And z score is x minus the mean divided by the standard deviation.
00:32
So for x equal to 69, z is 69 minus 60 divided by 12 or 0 .75.
00:45
For x being 54, z is 54 minus 60 divided by 12 or negative 0 .5.
00:57
And 8b, you want to go the other direction.
01:00
X is z times the standard deviation plus the mean with the same standard deviation in the mean.
01:10
So if z is 0 .5, then x is 0 .5 times 12 plus 60 or 66...