A student takes a 18-question, multiple-choice exam with four choices for each question and guesses on each question. Find the probability of guessing exactly 7 out of 18
Correctly.
A) 0.082
B) 0.918
C) 0.250
D) 0.389

Question

Quizplus · Accepted Answer

The probability of guessing exactly 7 out of 18 correctly can be calculated using the binomial probability formula: P(X = k) = (n choose k) * p^k * (1-p)^(n-k), where n = 18, k = 7, and p = 1/4 (since there are four choices for each question, giving a 1 in 4 chance of guessing correctly). Plugging these values into the formula gives a probability of approximately 0.082.

A Student Takes a 18-Question, Multiple-Choice Exam with Four Choices