If Judy,who forgot to study for the test,guesses on all questions,what is the probability that she will answer no more than 3 questions correctly?
A)0.839
B)0.111
C)0.949
D)0.617
E)0.162

Question

Quizplus · Accepted Answer

Assuming each question has four answer choices, the probability of Judy guessing a question correctly is 1/4. Using the binomial probability formula, we can calculate the probability of Judy getting no more than 3 questions correct out of a total of, say, 10 questions: P(X ≤ 3) = ∑ (10 choose x) * (1/4)^x * (3/4)^(10-x) where x goes from 0 to 3. This gives us the answer of approximately 0.839, which is closest to choice A.

If Judy,who Forgot to Study for the Test,guesses on All