00:01
This is the given probability mass function table here.
00:06
And the number of, so let's take a look at for part a, the problem that among 25 random niches in individuals.
00:13
So the sample size, which is given as 25 here.
00:17
So at least 15 have no citations.
00:19
So the probability of no citation, which is when y is equal to 0, 0 .40 here.
00:28
So that means the q value, which is 1 minus p here, that would be 1 minus 0 .40, that would be 0 .60 here.
00:39
So we have to select at least 25 hand no side tension.
00:44
So at this step, we're going to use the binomial distribution.
00:47
Let's say x be the random variable for this binomial distribution.
00:51
The n value here is 25 and the probability of the success, which is 0 .40 here.
00:56
So if it says at least 15, so the number of people should be 16, 15, 16, and 17 and so forth.
01:05
So the probability of the random variable x, which is greater than or equal to 15.
01:11
So i can just write this expression as the total probability, which is one, and the exclude part, which is x is less than or equal to 14.
01:22
So we can just get this value by using the normal and not normal.
01:28
So this is binom cdf function.
01:32
We can just use binom cdf application for the graphic display calculator.
01:38
So for the binom cdf, i'm going to just press the bottom second here and the distribution.
01:42
And there is binom cdf here.
01:45
Here we go.
01:46
So what we have to put, we have to put the total number of people here, which is 25.
01:50
And the probability value, which is 0 .4d, and the x value here, which is the 14 is included.
01:57
So i'm going to put the 14 here.
01:59
So i'm going to just write this number.
02:01
This is 25, and then 0 .40, and then 14...