00:01
Hi, i'm david and i'm here to have you answer your question.
00:04
Now let me bring up your question here.
00:06
In this question we're going to review about the binomial distribution.
00:11
Let me remind you that.
00:12
We have the x followed by the binomial with the n and the p and then the proper predict of the x equal to k, equal to n2k, p power k, 1 minus p power k.
00:28
Also, the mean of the x, it will equal to np, variance of the x equal to np 1 minus p.
00:38
Now a multiple choice test has 15 questions, so we have the n equal to the 15 questions.
00:45
Each question has five possible answers.
00:47
So probability to have a correct answer here, it will equal to 1 out of 5 or equal to 2.
00:54
If we call the x equal to the number of the correct answer, and then x it will follow by the binomial with the n equal to the 15, p equal to 0 .2.
01:15
Now the question i let x be the number of the question this student gets correct.
01:22
The distribution does x have some to answer it here already, and then for the b, one is the expected value of the correct answer...