00:01
Hi, i'm david and i'm here to help the answer your question.
00:03
Now let me bring up your question here.
00:06
In the question here, we are going to discuss about the normal distribution.
00:10
Let me remind you that if the x then followed by the normal with the mean standard deviation, if we turn the x minus the mean of a standard deviation, we obtain the standard normal.
00:21
Also, if we discuss about the sample mean x bar, it will minus the mean of standard deviation, we need to divide x2 squared of n.
00:29
In order to obtain the standard normal.
00:32
In the equation here we're given the x, it will follow by the normal, when the mean equal to the 156, sigma equal to the 43 .2, and equal to the 12.
00:45
In the question, i want to find the probability that one particular x will be greater than the 124 .8.
00:52
To find this probability, i need to convert the x into the z.
00:56
To do it, i need to apply the formula here.
00:58
So we turn the 124 .8 and minus the mean, divided by the standard deviation.
01:05
And if we compute, we have the z greater than 124 .8 minus 156 divided by the 43 .2, equal to the minus 0 .7 .2.
01:21
And now to find this probability, i need to bring up the z table.
01:25
So let me combine the z table.
01:27
And i put the table on the right here...