1. Let x be the number of courses for which a randomly selected student at a certain university is registered. The probability distribution of x appears in the table shown below: x 1 2 3 4 5 6 7 p(x) .04 .02 .08 .26 .35 .14 .11
(a) What is P(x = 4)? P(x = 4) =
(b) What is P(x 4)? P(x 4) =
(c) What is the probability that the selected student is taking at most five courses? P (at most 5 courses) =
(d) What is the probability that the selected student is taking at least five courses? more than five courses? P (at least 5 courses) = P (more than 5 courses) =
(e) Calculate P (3 x 6) and P(3 < x < 6). P (3 x 6) = P (3 < x < 6) =
2. Find the probability of the indicated event if P(A) = 0.25 and P(B) = 0.45. P(A ∪ B) if P(A ∩ B) = 0.1
3. How many arrangements of answers are possible for a true/false test with 7 questions?
4. In how many ways can a committee of 4 students be formed from a pool of 7 students?
5. As a financial planner, you are asked to select one stock each time from the following groups: 9 DOW stocks, 15 NASDAQ stocks, and 2 global stocks. How many different portfolios are possible?
6. A golf ball is selected at random from a container. If the container has 12 white balls, 8 green balls, and 4 orange balls, find the probability of the following event. The golf ball is not white.
7. Use the spinner shown in the figure below to find the probability indicated. Landing on blue or a consonant.
8. An urn contains 4 white marbles, 11 green marbles, 9 yellow marbles, and 7 black marbles. If one marble is selected, determine the probability that it is white.
9. The probability distribution of x, the number of defective tires on a randomly selected automobile checked at a certain inspection station, is given in the following table. x 0 1 2 3 4 p(x) .54 .14 .07 .04 .21
(a) Calculate the mean value of x. μx =
(b) What is the probability that x exceeds its mean value? P (x > μx) =
10. In a probability model, which of the following numbers could be the probability of an outcome? (Select all that apply.) 2/3 1/4 -1/4 1.4 0 3/4