Question: Do Problem of this section for the case that someone is taking a multiple choice test with five choices for each answer and guesses randomly when they don't know the answer.
Problem: Someone is taking a true-false test and guessing when they don't know the answer. We are going to compute a score by subtracting a percentage of the number of incorrect answers from the number of correct answers. When we convert this "corrected score" to a percentage score we want its expected value to be the percentage of the material being tested that the test-taker knows. How can we do this?