00:01
Hi, i'm david and i'm here to have the answer to your question.
00:04
Now let me bring up your question here.
00:07
In this question here we are going to discuss about the normal distribution.
00:12
Let me remind you that if the x that followed by the normal, with the mean and standard deviation, and then if we take the x will minus the mean of the standard deviation, we obtain the standard normal.
00:23
In this question here, we are given the time x will follow by the normal with the mean equal to the 12 minutes and the standard division equal to the 1 .5 minute.
00:35
The question asks, when you find the probability that there are something to take more than 40 minutes.
00:42
To find this probability, i need to convert the x into the z.
00:45
If you do it, i need to apply the formula here.
00:48
So i will take the 14 minus the mean over the standard deviation.
00:54
And if we compute, we will have the 2d, the 1.
00:59
5 .5 equal to the 1 .33...