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.
00:10
Let me remind you that if the x that follows by the normal, with the mean on the standard division, and if we take the x minus the mean of a standard division, we obtain the standard normal.
00:22
But if we turn the sum of mean x bar we minus the mean of a standard deviation, we need to divide extra and square of n in the job 10 standard normal.
00:30
In the question here we have the length of the number x, it will follow by the normal, when the mean equal to the 99, standard division equal to the 0 .4.
00:43
In the question a, we want to find the probability that the length x is greater than 99 .13.
00:53
Now to find this probability, i need to convert the xxx to the z.
00:56
To do it, i need to apply this formula here, and then i will have the 99 .13, we minus the mean, will be the 99 over the standard deviation.
01:08
And if we compute it, we will have the z.
01:10
It will be greater than 0 .113 divided by the 0 .4, equal to the 0 .3 -25.
01:18
Now to find this probability, i need to bring up the z table.
01:22
Let me copy the z table.
01:26
And we put the table on the right here.
01:31
Notice that the table i bring here, it has the negative g score with the probability on the left tail.
01:36
Right now it's not compatible with this probability yet.
01:39
It will try to draw the graph from the standard normal...