Two students taking a multiple choice exam with 20 questions and four choices for each question have the same, incorrect answer on eight of the problems. the probability that student b guesses the same incorrect answer as student a on a particular question is 1/4. if the student is guessing, it is reasonable to assume guesses for different problems are independent. the instructor for the class suspects the students exchanged answers. the teacher decides to present a statistical argument to substantiate the accusation. a possible model for the number of incorrect questions that agree is a:
a. anormal distribution with μ = 8 and σ = .25.
b. binomial distribution with n = 8 and p = .25.
c. normal distribution with μ = 20 and σ = .40.
d. binomial distribution with n = 20 and p = .40.