ST 101 ReilandLECTURE WORKSHEET #17
Name
1. A survey of local car dealers revealed that 64% of all cars sold last month had CD players, 28%
had alarm systems, and 22% had both CD players and alarm systems.
a. What is the probability that one of these cars selected at random had neither a CD player nor
an alarm system?
b. What is the probability that a car had a CD player unprotected by an alarm system?
c. Are having a CD player and an alarm system disjoint events?
2. A survey of an introductory statistics class in a previous semester asked students whether or not
they ate breakfast the morning of the survey. Results are as follows:
Yes No
Male 15 42 57
Female 22 37 59
37 79 116
Breakfast Total
Gender Total
a. What is the probability that a randomly selected student is a female?
b. What is the probability that a randomly selected student ate breakfast?
c. What is the probability that a randomly selected student is female and ate breakfast?
d. Given that a selected student is female, what is the probability that the student ate breakfast?
e. Given that a selected student ate breakfast, what is the probability that the student is female?
f. Does it appear that whether or not a student ate breakfast is independent of the student's
gender?
3. A typical social security number is 575-38-4444. How many social security numbers are
possible? How many social security numbers are possible if the first digit cannot be zero?
4. At they advertise that you can haveWendy's Old Fashioned Hamburgers,
hamburgers 256 ways. If they offer catsup, onion, mustard, pickles, lettuce,
tomato, mayonnaise, and relish, is their claim correct?
