00:02
Hello, so let's get our information down.
00:05
So we have a sample size of 64 taken from a normal population 24 taking from a normal population with a mean.
00:19
So our mean is 51 .4 and our standard division is 6 .8.
00:38
This is all you have to find you.
00:39
So we want to find a probability that the mean of the sample will exceed 2 .9.
00:46
So let's look at a, admitted that the mean will exceed 2 .9.
01:00
That's going to be equal to x bar minus mu over standard division divided by a square root of n for a normal distribution greater than 64.
01:21
There's double check.
01:23
Nope, that's my 64.
01:25
That's minus the mean, right? that's 51.
01:30
Divided by 6 .8 divided by a square root of n64.
01:39
So this here is just z greater than let's see what we got here.
01:48
So 52 .9, 1 .4, or divided 6 .8 by 8.
02:05
So we have 1 .76.
02:14
So this is the same as 1 minus probability of z.
02:21
Z plus and not equal to 1 .76.
02:27
So one minus.
02:31
So here we're going to have our probability from the z table.
02:38
We're going to go to the z table and look at z value of 1 .76.
02:45
And let's see what we got.
02:49
We have a probability of 0 .96 -080 and 680.
03:00
So the required probability.
03:02
Probability, it's going to be 1 minus .96, 0 .0 .0.
03:10
You have 0 .0392.
03:18
What's the kind of b? but the b, we want between 50 .5 and 153.
03:32
So 50 .5.
03:38
And the other one is 52 .3.
03:51
Okay...