Let X denote the number of hours you study during a randomly selected school day. The probability that X can take the values x, has the following where k is come unknown constant.
What is the probability of studying at most two hours?
Answer & explanation
Correct answer: option 4
P(at most two hours) = P(X<=2)
P(X<=2) = P(X=0) + P(X=1) + P(X=2)
= 0.1 + k + 2k = 3k + 0.1
= 3(0.15) + 0.1
= 0.55