Week 2 Homework and Quiz Review
1. True/False. 2.13 in valid probability. ANSWER: False
2. True/False. The union of two events is the probability of both events occurring. ANSWR: False
3. Determine if each variable below is discrete or continuous:
•Number of cars in the parking lot. ANSWER: Discrete
•Width of tree trunk. ANSWER: Continuous
4. Given: We have a sample space S with several events defined on it. S={2, 4, 6, 7, 9, 12}. And the
events are X={2, 6, 7} and Y={4, 6, 12}.
•What is contained in X ∩ Y? ANSWER: {6}
•What is contained in X U Y? ANSWER: {2, 4, 6, 7, 12}
•What is the complement of Y (NOT in Y) compare to original set? ANSWER: {2, 7, 9}
5. Consider the following probability of distribution of number of people we are likely to
find waiting in line at a restaurant.
Number waiting P(x)
0 .50
1 .30
2 .10
3 .10
•What is the average (mean)? ANSWER: 0.80
•What is the standard deviation? ANSWER: 0.98
•What is P(x=1)? ANSWER: 0.30
•What is P(x>1)? ANSWR: 0.20
6. Consider the following contingency table in which a sample of companies is summarized
in terms of the company’s industry type (manufacturing and retail) and country (US,
Canada, Mexico).
Manufacturin
g
Retail TOTAL
US 10 15 25
Canada 7 4 11
Mexico 6 3 9
TOTAL 23 22 45
