00:01
Hi, i'm david and i'm here to have you answer your question.
00:03
Now let me pick up your question here.
00:05
In this question here we are going to discuss about the normal distribution.
00:10
Let me remind you that if we have the x that follows by the normal, with the mean and the standard deviation, and if we turn the x will minus the mean over standard deviation, we'll obtain the standard normal.
00:21
But if we turn the sample mean am minus the mean over the standard deviation, we need to define x -char squared to the end.
00:28
Another to obtain the standard normal.
00:31
In this question here we have the x that follows by the normal with the mean it will equal to the 12 .5, standard division equals to the 1 .5.
00:42
And in the first question one, when you find the probability that the symbol n equals to the 25, that the probability of the average aim it will be exactly equal to the 13...