Question

A quiz consists of 50 multiple choice questions, each with five possible answers, only one of which is correct. Find the mean and the standard deviation of the number of correct answers

Answer 1

Answer:

$\mu=10\\\\\sigma=2.828$

Step-by-step explanation:

-This is a binomial probability  function.

-Given that the probability of success is p=0.2 and the sample size, n=50.

-The  mean is calculated using the formula:

$\mu=np\\\\=50\times 0.2\\\\=10$

-We then calculate the standard deviation as:

$\sigma=\sqrt{npq}, \ \ q=1-p\\\\=\sqrt{50\times 0.2(1-0.2)}\\\\=2.828$

Hence, the mean is 10 ad the standard deviation is 2.828