Question1

Points out of 5.00

You manage a small, boutique hotel catering to supper-affluent clients from around the world.You really want to better understand your clients so that you can serve them better.You are specifically interested in how far your clients travel to get to your hotel.In order to investigate this question you survey a random sample of 100 clients.Amongst this sample of clients, the average distance traveled was 984 miles.These results imply that the true population mean is exactly 984 miles?

Select one:

True

False

Question2

Points out of 5.00

Question text

On the same sample of 100 guests from the previous question, the lower bound of the 95% confidence interval is 934 miles while the upper bound is 1034 miles. What is the margin of error in this confidence interval?

Select one:

a.1025

b.1.96

c.100

d.50

Question3

Points out of 5.00

Question text

Given the results from question 1 and 2, which of the following statements is correct?

Select one:

a.There is a 95% chance that the true population mean is less than 1000.

b.I am 95% confident that the true population mean is more than 1000 miles.

c.I am not 95% confident that the true population mean is greater than 1000 miles.

d.There is a 95% chance that the true population mean is greater than 1000

Question4

Points out of 5.00

Question text

A news network stated that a study had found a positive correlation between the number of children a worker has and his or her earnings last year. You may conclude that:

Select one:

a.statisticians have small families.

b.people should have more children so they can get better jobs.

c.the data are erroneous because the correlation should be negative.

d.causation is in serious doubt.

Question5

Points out of 5.00

Question text

You are responsible for allocating budget within your organization. Several lines of business are asking for a limited set of marketing dollars. Therefore, you will need to make tough choices about which lines of business get the marketing dollars they want.Each team has presented a distribution of expected returns per marketing dollar. In all cases, the projected set of returns are normally distributed without outliers.You should most likely compare the mean expected return per marketing dollar in order to make your investment decision.

Select one:

True

False

Question6

Points out of 5.00

Question text

You are unsure about the distribution, mean, or median, of sales per customer. However, you know that the population standard deviation is $100. A sample of 100 customers revealed a mean of $200. Therefore, we can confidently say that the 95% confidence interval for mean sales is $200 +/- $19.6.

Select one:

True

False

Question7

Points out of 5.00

Question text

You are interested in the proportion of visitors who make a purchase on your company's website. You sample 150 visitors to the company's website.Fifty of those customers make a purchase. In order to calculate a 90% confidence interval you will need the t value associated with an alpha of .10 with 149 degrees of freedom.

Select one:

True

False

Question8

Points out of 5.00

Question text

The width of a confidence interval for the population mean isnotaffected by:

Select one:

a.the standard deviation.

b.the confidence level.

c.the sample size.

d.the sample mean.

Question 9:

Which of the following isnota valid description of an outlier?

Select one:

a.Outliers tend to impact the median more than the mean.

b.Outliers are values more than three standard deviations away from the mean.

c.Outliers are rare or unusual values within a given distribution.

Question10

Points out of 5.00

Question text

Based on the sample in the below table, it appears as though IPhone users are more than twice as likely than non-Iphone users to have a Panera rewards card.

Has Panera Card

No Panera Card

Total

IPhone User

n= 374

n=626

n=1000

Non-IPhone User

n=189

n=911

n=1100

Total

n=563

n=1537

N=2100

Select one:

True

False

Question11

Points out of 5.00

Question text

When confidence level decreases:

Select one:

a. decreases

b. doubles

c. increases

d. stays the same

Question12

Points out of 10.00

Question text

To estimate the average annual absentee hours of employees a random sample of 100 employee's annual absentee hours is taken. The sample mean is 54 and the population standard deviation is 7.4. The lower bound for the 95 percent confidence interval for the population mean is (enter the correct answer rounding to two significant digits (e.g. 3.14)):

Answer:

Question13

Points out of 10.00

Question text

Last week, 500 cars received parking violations in the main university parking lot. Of these, 49 had unpaid parking tickets from a previous violation. Assuming that last week was a random sample (and less than 10% of the entire population) of all parking violators, find the 99 percent confidence interval for the percentage of parking violators that have prior unpaid parking tickets. What is the margin of error (enter the answer rounding to two significant digits (e.g. 3.14))?

Answer:

Question14

Points out of 10.00

Question text

An emergency planning administrator needs an estimate of the mean weight of relief vehicles when fully loaded. She selects a random sample of 1000 trucks and finds a mean of 18 tons with a sample standard deviation of 7.4 tons. The width of the 95 percent confidence interval for the population mean is (enter the correct answer rounding to two significant digits (e.g. 3.14)) ?

Answer:

Question15

Points out of 5.00

Question text

You are interested in understanding your employees and their potential attrition.In order to understand what percentage of employees are likely to leave you anonymously survey 250 randomly chosen employees (out of over 20,000 employees in the company).You asked the question, "Do you expect to leave the organization in the next year?" Employees answered "yes" or "no".In the survey, 39 respondents answered "yes" they are likely to leave in the next year.What is the upper bound of the 95% confidence interval for the proportion of employees that are likely to leave in the next year (enter the correct answer rounding to two significant digits (e.g. 3.14)) ?

Answer:

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Your company is investigating quality of customer service in your organization.You take a sample of 400 calls and the average talk time (length of time spent with an agent) in the sample is 3.25 minutes.Based on previous analysis you know that the population standard deviation for all calls is 1.22 minutes.Calculate a 99% confidence interval for the average talk time.And then answer the following questions:

Question16

Points out of 3.00

Question text

In order to create a confidence interval for this problem do you use a t or z critical value?

Select one:

a.t critical value

b.z critical value

Question17

Points out of 3.00

Question text

What is the appropriate t or z critical value for this test (you may use table or excel, round to two significant digits (e.g. 3.14))?

Answer:

Question18

Points out of 4.00

Question text

What is the margin of error for this problem (round answers to two significant digits (e.g. 3.14)?

Answer: