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 this question here we're going to use the empirical rule and let me remind you about the empirical rule.
00:14
So suppose that we have the normal distribution and then the middle one will be the mean.
00:25
Now suppose that we move to the right by one standard deviation, another one standard deviation, one more standard deviation.
00:34
We do the same thing on the level, we will minus one standard deviation, minus one standard deviation, minus one standard deviations.
00:43
And the empirical rule says that within the one standard deviation, it will take up to the 68%.
00:49
Within the two standard deviation, it will take up to the 95%.
00:56
And within the three standard deviations, it will take up to the 99 .7%.
01:02
Now in this question here, we have the length.
01:04
On the movie 5 it will follow by the normal with the mean now it will equal to the 189 .4 so the middle v here it will be the mean and it will equal to the 189 .4 minute.
01:20
And then we are given the standard division equal to the 20 .1.
01:25
So here percentage of total area shaded here i don't know what option you have here but i will do the one with the 68 % first.
01:34
For the 68 % we will have this one will be one standard deviation on the left.
01:41
This one will be one standard division on the right.
01:44
So therefore, the value here, it will use the 68%.
01:50
It will be by the formula will be the mu minus one standard division...