Math 1280 Final Exam/ Quizzes with Correct
Ans/ 2025.
You are interested in the number of English-speaking people on the planet who want to play a
new kind of online video game. You asked 300 college students if they were interested in playing
video games, 100 said yes, and of them 20 preferred your game to an existing game that is
widely used. How many people were in the sample?
Select one: a. The number of English-speaking people on the planet who want to play a new
kind of online video game. b. 300 c. 200 d. 100 e. 20 - Answer: b
What is the mean of x? x <- c(12, 14, 11, 14, 13, 15, 12, 16, 10)
Select one: a. 12 b. 13 c. 14 d. 15 e. 16 - Answer: b
Select one: a. ppois(6, 4) - ppois(3, 4) b. ppois(6, lambda=4) - ppois(4, lambda=4) c. ppois(5, 4) -
ppois(3, 4) d. ppois(5, 4) - ppois(4, 4) e. ppois(6 - 4, lambda=4) - Answer: c
Page 1 of 5
, At a small store, a customer enters the front door on average every 8 minutes. A prior study
indicated that the time between customers entering the front door during weekdays follows an
exponential distribution. What is the probability that the time between customers entering the
store on a weekday will be less than or equal to 7?
Select one: a. .62 b. .43 c. 1/8 d. 7/8
e. .58 - Answer: e
You read a research paper that applies to your industry, and it says that when people are given a
list of facts about your product, they are more likely to buy your product and that the difference
between the regular amount of sales and the sales when people read the list of facts is 3
standard deviations. How would you describe the difference of 3 standard deviations (select the
best answer)?
Select one: a. Cannot tell because the units are not specified. b. It is a small difference because
3 is a small number. c. It is an important difference because a 3 standard deviation difference
would be expected due to random chance in less than 1% of the cases. d. It is NOT an important
difference because with each sample there is variation and the difference could be due to
chance. e. Cannot tell because the sample size is not given. - Answer: c
Use the following information for the next three questions.
At a medium sized airport, mechanics need to replace tires on some of the airplanes each week
because the tread on the tires is below the safe limit. You collected 36 weeks of data and
observed that the numbers followed a Poisson distribution and that there was an average of 2
tires replaced per week. - Answer:
Page 2 of 5
Ans/ 2025.
You are interested in the number of English-speaking people on the planet who want to play a
new kind of online video game. You asked 300 college students if they were interested in playing
video games, 100 said yes, and of them 20 preferred your game to an existing game that is
widely used. How many people were in the sample?
Select one: a. The number of English-speaking people on the planet who want to play a new
kind of online video game. b. 300 c. 200 d. 100 e. 20 - Answer: b
What is the mean of x? x <- c(12, 14, 11, 14, 13, 15, 12, 16, 10)
Select one: a. 12 b. 13 c. 14 d. 15 e. 16 - Answer: b
Select one: a. ppois(6, 4) - ppois(3, 4) b. ppois(6, lambda=4) - ppois(4, lambda=4) c. ppois(5, 4) -
ppois(3, 4) d. ppois(5, 4) - ppois(4, 4) e. ppois(6 - 4, lambda=4) - Answer: c
Page 1 of 5
, At a small store, a customer enters the front door on average every 8 minutes. A prior study
indicated that the time between customers entering the front door during weekdays follows an
exponential distribution. What is the probability that the time between customers entering the
store on a weekday will be less than or equal to 7?
Select one: a. .62 b. .43 c. 1/8 d. 7/8
e. .58 - Answer: e
You read a research paper that applies to your industry, and it says that when people are given a
list of facts about your product, they are more likely to buy your product and that the difference
between the regular amount of sales and the sales when people read the list of facts is 3
standard deviations. How would you describe the difference of 3 standard deviations (select the
best answer)?
Select one: a. Cannot tell because the units are not specified. b. It is a small difference because
3 is a small number. c. It is an important difference because a 3 standard deviation difference
would be expected due to random chance in less than 1% of the cases. d. It is NOT an important
difference because with each sample there is variation and the difference could be due to
chance. e. Cannot tell because the sample size is not given. - Answer: c
Use the following information for the next three questions.
At a medium sized airport, mechanics need to replace tires on some of the airplanes each week
because the tread on the tires is below the safe limit. You collected 36 weeks of data and
observed that the numbers followed a Poisson distribution and that there was an average of 2
tires replaced per week. - Answer:
Page 2 of 5
