On a multiple choice test with 26 questions, each question has four possible answers, one of which is correct. For students who guess at all answers, find the standard deviation for the number of correct answers.
A) 48.8
B) 23.8
C) 2.2
D) 4.9

Question

Quizplus · Accepted Answer

The standard deviation for a binomial distribution is calculated using the formula √(n * p * (1-p)), where n is the number of trials (questions) and p is the probability of success (correct answer). Here, n = 26 and p = 1/4. So, the standard deviation is √(26 * 1/4 * 3/4) = √(4.875) ≈ 2.2.

On a Multiple Choice Test with 26 Questions, Each Question