Please confirm if this correct in incorrect please correct without explanation.

Question 1 Not yet answered Marked out of 1.00

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

Clear my choice

Question 2 Not yet answered Marked out of 1.00

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

Clear my choice

Question 3 Not yet answered Marked out of 1.00

Using the value of x from the prior question, what is the standard deviation of x?

Select one:

a. 1

b. 3.75

c. 9

d. sqrt(13)

e. 1.94

Clear my choice

Question 4 Not yet answered Marked out of 1.00

There was a very short quiz with ve questions. The following table shows the

number of correct answers and the cumulative relative frequency for those scores in

the class.

value: 2 3 4 5

cumulative

relative

frequency:

.13 .55 .925 1

What is the probability that a randomly selected student from the class scored a 3 on

the short quiz?

Select one:

a. .13

b. .42

c. .55

d. .375

e. .925

Clear my choice

Information

Use this information for the next three questions.

A random variable called L is dened by the following table, but one of the relative

frequencies is missing:

value: -5 0 1 3 8

relative

frequency:

.17 .11 .23 .15

Question 5 Not yet answered Marked out of 1.00

What is the missing value in the list of relative frequencies for random variable L?

Select one:

a. .34

b. .23

c. .19

d. .17

e. .11

Clear my choice

Catherine Petagno

Home My courses MATH 1280 - AY2021-T3 Final Exam (Days 1 - 4) Final Exam (Proctored)

Question 6 Not yet answered Marked out of 1.00

What is the probability that a randomly selected item from random variable L will be

greater than 0 and less than or equal to 3?

Select one:

a. .00

b. .57

c. .23

d. .85

e. 1

Clear my choice

Question 7 Not yet answered Marked out of 1.00

What is the expectation of random variable L?

Select one:

a. .00

b. .23

c. 1.14

d. 1.60

e. 1.83

Clear my choice

Question 8 Not yet answered Marked out of 1.00

What is the variance of random variable L?

Select one:

a. 1.60

b. 2.30

c. 3.46

d. 7.23

e. 14.58

Clear my choice

Question 9 Not yet answered Marked out of 1.00

Which distributions are discrete?

Select one:

a. the normal distribution and the Poisson distribution.

b. the Poisson distribution, the binomial distribution, and the uniform distribution.

c. the binomial distribution and the exponential distribution.

d. the Poisson distribution, the binomial distribution, and the normal distribution.

e. none of the answers above are accurate

Clear my choice

Question 10 Not yet answered Marked out of 1.00

What is the expected number of successes (balloons popped) when throwing 5 darts

(rounded to two decimal places)?

Select one:

a. 1.41

b. 1.00

c. 2.50

d. 0.75

e. 0.50

Question 11 Not yet answered Marked out of 1.00

What is the probability of getting 4 or more successes (popped balloons) in 5 throws

(rounded to two decimal places)?

Select one:

a. .00

b. .98

c. .07

d. .33

e. .12

Clear my choice

Question 12 Not yet answered Marked out of 1.00

A Poisson distribution called Q has an expectation of 4. Which of the following R

commands would tell you the probability that a randomly selected value from Q is

less than 6 and greater than or equal to 4 (read the question carefully):

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)

Clear my choice

Question 13 Not yet answered Marked out of 1.00

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

Clear my choice

Question 14 Not yet answered Marked out of 1.00

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 dierence 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 dierence of 3 standard deviations (select the best answer)?

Select one:

a. Can not tell because the units are not specied.

b. It is a small dierence because 3 is a small number.

c. It is an important dierence because a 3 standard deviation dierence would be

expected due to random chance in less than 1% of the cases.

d. It is NOT an important dierence because with each sample there is variation and the

dierence could be due to chance.

e. Can not tell because the sample size is not given.

Clear my choice

Information

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.

Question 15 Not yet answered Marked out of 1.00

What is the lambda value for the Poisson distribution?

Select one:

a. 0

b. 1/2

c. 1

d. 2

e. sqrt(1/2)

Question 16 Not yet answered Marked out of 1.00

If we know that the expectation is 2, what is the standard deviation of the Poisson

distribution?

Select one:

a. 1/2

b. sqrt(2)

c. 1 / sqrt(2)

d. 2

e. 2 / sqrt(n)

Clear my choice

Question 17 Not yet answered Marked out of 1.00

Trac at the airport changed recently, and you collected 36 weeks of data in an

eort to estimate the new rate of tire replacements. You found that the average tire

replacements per week was 2 and the numbers followed a Poisson distribution, but

you realize that your sample might not be 100% accurate. What is the 99th

percentile of sampling distribution of the mean of tires replaced per week (based on

the observed mean of 2 and the sample size of 36)?

Select one:

a. qnorm(.99, mean=2, sd=sqrt(1/2))

b. pnorm(.99, mean=2, sd=2)

c. pnorm(.99, mean=2, sd=1/sqrt(2))

d. qnorm(.99, mean=2, sd=sqrt(2)/6)

e. qnorm(.99, mean=2, sd=1/2

Clear my choice

Question 18 Not yet answered Marked out of 1.00

The mean weekly sales per employee at a nationwide store is normally distributed

with a mean of $7,300 per week and a standard deviation of $700. What is the

probability that a randomly selected employee will have sales less than $6,500?

Select one:

a. .03

b. .13

c. .23

d. .33

e. .43

Question 19 Not yet answered Marked out of 1.00

The the time between incoming customer service calls to a computer-repair hotline

follows an exponential distribution with an expectation of 2 minutes between calls.

What is the probability that the time between calls will be less than 1 minute for a

randomly selected period?

Select one:

a. .44

b. .31

c. .39

d. .61

e. .07

Clear my choice

Question 20 Not yet answered Marked out of 1.00

The time between customer service calls to a computer-repair hotline follows an

exponential distribution with an expectation of 2 minutes between calls. We collect

calls for 40 minutes at random times during the month (a sample of size n=40).

What is the probability that the mean of our sampling distribution will be greater

than 2.2 minutes?

Select one:

a. .17

b. .26

c. .37

d. .68

e. .78

Clear my choice

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