A multiple choice test has 4 questions. For a subject making random guesses for each answer, the probabilities for the number of correct responses are given in the table below. Assume that a subject makes random guesses for each question.

X | P(X)

______

0 | 0.4096

1 | 0.4096

2 | 0.1536

3 | 0.0256

4 | 0.0016

a. Is the given probability distribution a binomial probability distribution?

b. Find the probability of getting at least one correct answer

c. Find the probability of getting all correct answer

d. Find Mean and Sigma^2