00:01
There is given a normal distribution for this question.
00:04
The mean value was given.
00:05
So the mean, which is denoted by moot, this is 266.
00:09
And the standard deviation, which is denoted by sigma, that was given as 17 days.
00:16
And i can define the random variable x, which is normally distributed to 66 and 17.
00:22
So what we're going to find in part a, we need to find the percentage of the pregnancies should loss between.
00:29
So we need to get the probability of random variable x, which is between 268 and 277.
00:36
In order to get this probability, i'm going to use the normal cdf function for the graphing display calculator.
00:41
The lower boundary is 268, the upper boundary is 277, and the mean value is 266 and the standard division, which is 17.
00:51
Let's get the answer.
00:53
Press second.
00:54
Press second variance, the second option here.
00:56
The lower boundary, 268, and the upper boundary is 277.
01:01
And the mean is to 66 and the standard division which is 17 so we will get the answer as 0 .19 and 44 this is the answer we have for but we have to give the answer with two decimal places so the answer would be 0 .19 and what about for part b at least how many days should the longest 30 so the least value the least value b x1 so what that means graph graphically, if you graph the normal distribution, there should be x1 here, and the area of this region would be 30%.
01:38
It can write as 0 .3...