00:01
Hi, i'm david and i'm here to help you answer your question.
00:04
Now let me bring up your question here.
00:06
In the question here, we are going to discuss about the normal distribution.
00:11
Let me remind to you that if when the x that follows by the normal with the mean and standard deviation, it will tell the x minus the mean of a standard deviation when obtain the standard normal.
00:22
But if the sum of mean x bar we minus the mean of a standard deviation, we need to define x -chard square to n, another job 10, standard normal.
00:31
In the question here we have the weight of the pupil x will follow by the normal, when the mean equal to the 165, standard division equal to the 35.
00:43
In the question a, for the one single person and want to find the weight, it will be greater than the 160.
00:52
To find this probability, i need to convert the x into the z.
00:55
To do it and i need to apply this formula here and then we get equal to the 160 and minus the mean divided by the standard deviation and when we compute we get equal to the probability greater than minus 5 divided 35 equal to the minus 0 .14 and to find this probability let me bring up the z table and we'll put the table on the right here notice that the table i bring here it has the negative with the probability on the left tail.
01:35
Right now it's not compatible with this probability.
01:38
It will try to draw the graph of the standard normal.
01:41
We will have the bell curve.
01:43
The middle value will be the 0.
01:45
Suppose this will be the minus 0 .14.
01:48
And then the probability we're looking for equals to the area on the right tail...