Final answer:
The mean for choosing the correct answers on a 13-question multiple-choice test with 4 possible answers per question is the constant probability of choosing a single correct answer: 0.25.
Step-by-step explanation:
You asked about the mean for choosing the correct answers on a multiple-choice test with 13 questions, each with 4 possible answers and only 1 correct answer. To find the mean, or expected value, for the number of correct answers when guessing randomly, we can multiply the probability of getting a single question correct by the total number of questions. Since there is only one correct answer out of four possible choices, the probability of picking the correct answer for one question is ⅔ or 0.25. By multiplying this by the total of 13 questions, we would get 13 x 0.25, which equals 3.25. Therefore, the mean number of correct answers when guessing randomly would be approximately 3.25 out of 13. However, this does not directly answer the multiple-choice options provided. Our question, though, asks for the mean probability, not the mean number of correct answers, and since the likelihood of choosing the right answer for a single question remains constant at 0.25, option A) 0.25 is the correct answer to your question.