OIS 2340 Ch. 4 HW Questions with
complete solution 2025/2026
Three events occur with probabilities P(E1) = 0.35, P(E2) = 0.15, P(E3) = 0.40. If the event B occurs, the
probability becomes P(E1|B) = 0.25, P(B) = 0.30. Compute P(E1 or B). - correct answer ✔0.575
Cross County Bicycles makes two mountain bike models that each come in three colors. The following
table shows the production volumes for last week:
Model Blue Brown White
XB-50 302 105 200
YZ-99 40 205 130
What is the joint probability that a product manufactured is a YZ-99 and brown? - correct answer
✔0.2088
Of the last 100 customers entering a computer shop, 25 have purchased a computer. If the classical
probability assessment for computing probability is used, the probability that the next customer will
purchase a computer is: - correct answer ✔0.50
Micron Technology has sales offices located in four cities: Dallas, Seattle, Boston, and Los Angeles. An
analysis of the company's accounts receivables reveals the number of overdue invoices by days, as
shown here.
Days Overdue Dal. Sea. Bos. LA
Under 30 days 137 122 198 287
30-60 days 85 46 76 109
61-90 days 33 27 55 48
Over 90 days 18 32 45 66
, Assume the invoices are stored and managed from a central database.
If a randomly selected invoice is from the Los Angeles office, what is the probability that it is 60 or fewer
days overdue? - correct answer ✔0.7765
The Anderson Lumber Company has three sawmills that produce boards of different lengths. The
following table is a joint frequency distribution based on a random sample of 1,000 boards selected
from the lumber inventory.
Board Length
Sawmill 8 ft 10 ft 12 ft 14 ft
A 140 100 80 14
B 250 20 100 50
C 160 50 16 20
Based on these data, the probability of selecting a board from inventory that is 10 feet long is: - correct
answer ✔0.170
Drake Marketing and Promotions has randomly surveyed 200 men who watch professional sports. The
men were separated according to their educational level (college degree or not) and whether they
preferred the NBA or the National Football League (NFL). The results of the survey are shown:
SportPref Degree No Degree
NBA 40 55
NFL 10 95
What is the probability that a randomly selected survey participant prefers the NFL? - correct answer
✔0.5250
complete solution 2025/2026
Three events occur with probabilities P(E1) = 0.35, P(E2) = 0.15, P(E3) = 0.40. If the event B occurs, the
probability becomes P(E1|B) = 0.25, P(B) = 0.30. Compute P(E1 or B). - correct answer ✔0.575
Cross County Bicycles makes two mountain bike models that each come in three colors. The following
table shows the production volumes for last week:
Model Blue Brown White
XB-50 302 105 200
YZ-99 40 205 130
What is the joint probability that a product manufactured is a YZ-99 and brown? - correct answer
✔0.2088
Of the last 100 customers entering a computer shop, 25 have purchased a computer. If the classical
probability assessment for computing probability is used, the probability that the next customer will
purchase a computer is: - correct answer ✔0.50
Micron Technology has sales offices located in four cities: Dallas, Seattle, Boston, and Los Angeles. An
analysis of the company's accounts receivables reveals the number of overdue invoices by days, as
shown here.
Days Overdue Dal. Sea. Bos. LA
Under 30 days 137 122 198 287
30-60 days 85 46 76 109
61-90 days 33 27 55 48
Over 90 days 18 32 45 66
, Assume the invoices are stored and managed from a central database.
If a randomly selected invoice is from the Los Angeles office, what is the probability that it is 60 or fewer
days overdue? - correct answer ✔0.7765
The Anderson Lumber Company has three sawmills that produce boards of different lengths. The
following table is a joint frequency distribution based on a random sample of 1,000 boards selected
from the lumber inventory.
Board Length
Sawmill 8 ft 10 ft 12 ft 14 ft
A 140 100 80 14
B 250 20 100 50
C 160 50 16 20
Based on these data, the probability of selecting a board from inventory that is 10 feet long is: - correct
answer ✔0.170
Drake Marketing and Promotions has randomly surveyed 200 men who watch professional sports. The
men were separated according to their educational level (college degree or not) and whether they
preferred the NBA or the National Football League (NFL). The results of the survey are shown:
SportPref Degree No Degree
NBA 40 55
NFL 10 95
What is the probability that a randomly selected survey participant prefers the NFL? - correct answer
✔0.5250
