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 are going to discuss about the binomial distribution.
00:11
Let me remind you that even the x that followed by the binomial with the n and the b and then the probability of the x equal to k, equal to n choose k, b power k, times 1 minus b, power n minus k.
00:26
And we have the mean u equal to the n times b.
00:30
The variant sigma square equal to n times b times 1 minus b and in this question here we have the symbol n equal to the 20 and we have the b equal to the 0 .8 and here we will define the x equal to the number of the computer that have virus and then we see that the x it will follow by the binomial with the n, it will equal to the 20, and p equal to the 0 .8.
01:14
And now in this question here, the question is going to find the mean and the variance.
01:21
So therefore, want to find the e of the x, which is equal to the mu.
01:25
So it's equal to the formula here, equal to n times p, equal to the 20 times 0 .8, and it will equal to the 1 .6, as will equal to the 16.
01:39
Now for the variance sigma square, it's equal to this formula.
01:44
So equal to the n times b times 1 minus b, equal to the 20 times 0 .8 times 1 minus 0 .8...