00:01
There is given a normal distribution in this question, so the population mean, that was given as 82, and the population standard deviation denoted by sigma, that was given as 9, and the sample size given here, which is 25.
00:12
Because the population has the normal distribution, any sample from this normal population should be again a normal distribution.
00:20
So what i need, i need the sample mean, the sample mean is the same with the population mean, which is 82, and also i need the sample standard deviation.
00:29
In order to get the sample standard division, i'm going to divide the population standard division by square root of the sample size.
00:35
Let me just find this value, this is 9 over square root of 25, which is 9 over 5, this is 1 .8.
00:41
I can define a random variable x bar for the sample, normally distributed, so the mean and the standard division...