BUS 204 Week 10 Assignment

BUS 204 Week 10 Assignment | MiraCosta College

1.

In the Bed Bath and Beyond practice problem, what is the MARGIN OF ERROR for the population proportion? Round your answer to four decimal places.  0.1067

2.

Determine the

80%

confidence interval estimate for the population mean of a normal distribution given

n=121,

σ=135,

and

x=1,300.

The

80%

confidence interval for the population mean is from

to

 (Round to two decimal places as needed. Use ascending order.)

 

3.

random sample of

n=12

values taken from a normally distributed population resulted in the sample values below. Use the sample information to construct

a

99%

confidence interval estimate for the population mean.

91           108         90           104         111         107         112         110         92           111         95           99              

The

99%

confidence interval is from

to

 

(Round to two decimal places as needed. Use ascending order.)

 

4.

As a follow-up to a report on gas consumption, a consumer group conducted a study of SUV owners to estimate the mean mileage for their vehicles. A simple random sample of

97

SUV owners was selected, and the owners were asked to report their highway mileage. The results that were summarized from the sample data were

x=18.5

mpg and

s=5.1

mpg. Based on these sample data, compute and interpret a

95%

confidence interval estimate for the mean highway mileage for SUVs.

The

95%

confidence interval is

mpg––––––mpg.

(Round to one decimal place as needed. Use ascending order.)

Interpret this interval. Choose the correct answer below.

 

A.

One can conclude with

95%

confidence that the true mean highway mpg for SUVs is in this range.

Your answer is correct.

 

B.

There is a

0.95

probability that the true mean highway mpg for SUVs falls in this range.

 

C.

One can conclude with

95%

confidence that the sample mean highway mpg for SUVs is in this range.

 

D.

One can conclude that the true mean highway mpg for SUVs will fall in this range

95%

of the time.

 

5.

An advertising company wishes to estimate the mean household income for all single working professionals who own a foreign automobile. If the advertising company wants a

99%

confidence interval estimate with a margin of error of

±2500,

what sample size is needed if the population standard deviation is known to be

$26,500?

The sample size must be at least

.

(Round up to the nearest whole number.)

 

6.

An airline is considering charging a two-tiered rate for checked bags based on their weight. Before deciding at what weight to increase the rate, the airline wishes to estimate the mean weight per bag checked by passengers. It wants the estimate to be within

±0.50

pounds of the true population mean. A pilot sample of checked bags produced the results shown below.

47           37           37           40           42           34           38           35           31           40          

45           45           47           43           35           35           35           35           37           49          

a.            What sample size should the airline use if it wants to have

95%

confidence?

b.            Suppose the airline managers do not want to take as large a sample as the one determined in part a. What general options do they have to lower the required sample size?

a. The sample size must be at least

.

(Round up to the nearest whole number.)

b. What could the managers do to lower the required sample size? Select all that apply.

 

A.

Reduce the level of confidence

Your answer is correct.

 

B.

Increase the population standard deviation

 

C.

Increase the margin of error

Your answer is correct.

 

D.

Use a larger pilot sample

 

7.

A magazine company is planning to survey customers to determine the proportion who will renew their subscription for the coming year. The magazine wants to estimate the population proportion with

95%

confidence and a margin of error equal to

±0.07.

What sample size is required?

 

Click the icon to view a table of critical values for commonly used confidence levels.

The required sample size is

customers.

 

8.

Suppose that a safety group surveyed

1,300

drivers. Among those surveyed,

75%

said that careless or aggressive driving was the biggest threat on the road, and

39%

said that cell phone usage by other drivers was the driving behavior that annoyed them the most. Based on these data and assuming that the sample was a simple random sample, construct and interpret a

95%

confidence interval estimate for the true proportion in the population of all drivers who are annoyed by cell phone users.

The confidence interval estimate is

 (Round to three decimal places as needed. Use ascending order.)

Interpret the confidence interval estimate.

 

A.

There is a

0.95

probability that the sample proportion of drivers who are annoyed by cell phone users is in the interval.

 

B.

There is

95%

confidence that the population proportion of drivers who are annoyed by cell phone users is equal to one of the bounds of the interval.

 

C.There is a

0.95

probability that the population proportion of drivers who are annoyed by cell phone users is in the interval.

 

D.There is

95%

confidence that the population proportion of drivers who are annoyed by cell phone users is in the interval.

s