00:01
Okay, so here we have a normal distribution with a mean of 163 .5 and a standard deviation of 51 .7.
00:11
And we are taking a sample of size 152.
00:15
First, though, we need to find the probability that one single randomly generated value is greater than 168 .1.
00:23
So we're looking basically for this probability here.
00:27
Right so to find that we'll just use the normal z formula and do x minus mu over sigma um x in this case being the 168 .1 minus the mean over sigma the standard deviation okay when i calculate that in my calculator 168 .1 minus 163 .5 divided by so i'll do that 4 .6 and then divide by the 51 .7 i get 0 .09 for my z value.
01:04
Okay.
01:05
However, that is not my probability.
01:07
I need to look up that number and remember that the z table, when i look things up on it, gives me the probability that it's below.
01:14
So i'll need to do 1 minus the value that i get.
01:17
So looking that up on my z table really quickly, when i look up 0 .09, okay, i get, sorry looking at 0 .09.
01:33
Okay, so when i look up, so i go to the 0 .0 row and then all the way to the 0 .9, and i get 0 .5359.
01:42
But remember i need 1 minus that value...