00:01
Okay, in this case, we're going to get to the following question, and the important thing to remember is we can use a z score when the sample size is squared equal to 30 as is in this case, and the formula simply is z is equal to x bar minus mu all over the standard deviation divided by a square of it.
00:21
And in this case, you might be wondering what all these terms mean here.
00:25
So x bar is simply known as the sample, mean weight, which is 89 kgs.
00:34
Mu is known as a population mean weight, which is 90 kgs.
00:39
Sigma is known as a standard deviation, which is 82 kg.
00:44
And finally, n is simply a sample size.
00:46
In this case, it's 40, and those are students.
00:49
So 40 students...