Probability Review

Multiple Choice

Identify the choice that best completes the statement or answers the question.

____1.Lynn and Dawn tossed a coin 60 times and got heads 33 times. What is the experimental probability of tossing heads using Lynn and Dawn’s results?

____2.A biologist has determined that a particular osprey has a 70% chance of catching a fish on any given day. Carry out a simulation of twenty trials using the random number table below to find the probability that the osprey will actually catch a fish on all of the next three days. Explain your method.

945 / 025 / 354 / 793 / 236
106 / 746 / 981 / 105 / 012
832 / 180 / 250 / 871 / 835
793 / 726 / 864 / 496 / 947
a. / Using the digits 0–7 to represent a caught fish, the probability of catching a fish on each of the next three days is 70%.
b. / Using the digits 0–7 to represent a caught fish, the probability of catching a fish on each of the next three days is 65%.
c. / Using the digits 0–6 to represent a caught fish, the probability of catching a fish on each of the next three days is 35%.
d. / Using the digits 0–7 to represent a caught fish, the probability of catching a fish on each of the next three days is 7%.

____3.The theoretical probability of an event is ____ a negative number.

a. / always / b. / sometimes / c. / never

____4.If a dart hits the target at random, what is the probability that it will land in the shaded region?

Suppose Q and R are independent events. Find P(Q and R).

____5.P(Q) = 0.4, P(R) = 0.49

____6.P(Q) = 2/5, P(R) = 3/5

____7.Two urns contain white balls and yellow balls. The first urn contains 5 white balls and 5 yellow balls and the second urn contains 7 white balls and 4 yellow balls. A ball is drawn at random from each urn. What is the probability that both balls are white?

Suppose S and T are mutually exclusive events. Find P(S or T).

____8.P(S) = 2%, P(T) = 22%

____9.P(S) = 2/5, P(T) =

____10.What is the probability that a spin of the spinner will land on a purplesection or odd number?

____11.The table shows the results of a survey of students in two math classes.

Find P(less than 1 hour of TV | 3rd period class). Round to the nearest thousandth.

Did You Watch More Than One Hour of TV Last Night?

Yes / No
3rd period class / 11 / 6
6th period class / 13 / 10

____12.The table shows the results of a survey of college students. Find the probability that a student is taking a humanities class, given the student is male. Round to the nearest thousandth.

First Class of the Day for College Students

Male / Female
Humanities / 70 / 80
Science / 50 / 80
Other / 60 / 70
a. / 0.171 / b. / 0.467 / c. / 0.269 / d. / 0.389

____13.Each person in a group of students was identified by year and asked when he or she preferred taking classes: in the morning, afternoon, or evening. The results are shown in the table. Find the probability that the student preferred evening classes given he or she is a freshman. Round to the nearest thousandth.

When Do You Prefer to Take Classes?

Freshman / Sophomore / Junior / Senior
Morning / 19 / 2 / 6 / 16
Afternoon / 17 / 3 / 13 / 15
Evening / 8 / 14 / 9 / 7

____14.A class of 40 students has 11 honor students and 10 athletes. Three of the honor students are also athletes. One student is chosen at random. Find the probability that this student is an athlete if it is known that the student is not an honor student. Round to the nearest thousandth.

a. / 0.241 / b. / 0.345 / c. / 0.252 / d. / 0.034