Question

Let x be the number of students who show up for a professor's office hour on a particular day. Suppose that the pmf of x is p(0) = 0.20, p(1) = 0.15, p(2) = 0.30, p(3) = 0.25, and p(4) = 0.10. What is the probability that at least 2 students show up for the office hour?

1) 0.55
2) 0.60
3) 0.65
4) 0.70

Answer 1

The probability that at least 2 students show up is 0.65.

Step-by-step explanation:

To find the probability that at least 2 students show up for the office hour, we need to sum the probabilities for all the values of x greater than or equal to 2.

P(x ≥ 2) = P(x = 2) + P(x = 3) + P(x = 4) = 0.30 + 0.25 + 0.10 = 0.65.

Therefore, the probability that at least 2 students show up for the office hour is 0.65. Option 3) 0.65 is the correct answer.