Moore et al-The Practice of Business Statistics (Homework)

James Finch

Statistics, section 2, Fall 2019

Instructor: Dr. Friendly

Current Score : 2 / 13

Due : Sunday, January 27, 2030 23:30 EST

Last Saved : n/a Saving... ()

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Question

Points

1	2	3	4	5
–/6	–/2	2/2	–/2	–/1

Total

2/13 (15.4%)

Instructions

Here are some textbook questions from The Practice of Business Statistics 1/e by David S. Moore, George P. McCabe, William M. Duckworth, and Stanley L. Sclove published by W. H. Freeman. Click here for a list of all of the questions coded in WebAssign. This demo assignment allows many submissions and allows you to try another version of the same question for practice.

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For this assignment, you submit answers by question parts. The number of submissions remaining for each question part only changes if you submit or change the answer.

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Your last submission is used for your score.

1. –/6 points MBusStat1 1.E.041. My Notes

National Fuelsaver Corporation manufactures the Platinum Gasaver, a device they claim "may increase gas mileage by 22%." In an advertisement, the gas mileages with and without the device were presented for 15 "identical" 5-liter vehicles. The percent changes in gas mileage for the vehicles were calculated and are presented below.

49.0	46.9	46.8	44.1	40.2	38.5	34.6	33.7
28.7	28.7	24.8	10.8	10.4	6.4	-15.5

The 15.5% decrease in gas mileage is an outlier in this data set.

(a) Find the mean x and the standard deviation s.

x	=
s	=

(b) Find x and s for the 14 observations that remain when you ignore the outlier.

x	=
s	=

How does the outlier affect the values of x and s?

The outlier causes the signs but not values to change for the mean and standard deviation. The outlier inflates s and the mean because the outlier was higher than the mean. The outlier inflates s, but reduces the mean because the outlier was lower than the mean. The outlier does not significantly affect the mean and standard deviation.

The vehicles all are the same color. The vehicles all get the exact same gas mileage. The vehicles are similar in make, model, year.

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2. –/2 points MBusStat1 2.E.022. My Notes

Answer the following questions.

(a) If a store always prices its generic "store brand" products at 95% of the brand name products' prices, what would be the correlation between the prices of the brand name products and the store brand products? (Hint: Draw a scatterplot for several prices.)

The correlation coefficient should be 0.95. There is not any one correlation coefficient that fits all the points. The correlation coefficient should be 0.05. The correlation coefficient should be 1.0. Every point will fall on the same line.

(b) If the store always prices its generic products $1.50 less than the corresponding brand name products, then what would be the correlation between the prices of the brand name products and the store brand products?

There is not any one correlation coefficient that fits all the points. The correlation coefficient should be 1/1.50. The correlation coefficient should be 1.0. Every point will fall on the same line. The correlation coefficient should be 1.50.

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3. 2/2 points | Previous Answers MBusStat1 3.E.058. My Notes

A telemarketing firm in Los Angeles uses a device that dials residential telephone numbers in that city at random. Of the first 100 numbers dialed, 43 are unlisted. This is not surprising, because 53% of all Los Angeles residential phones are unlisted. Which of the bold numbers is a parameter and which is a statistic?

43% is a

.

53% is a

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4. –/2 points MBusStat1 4.E.016. My Notes

A Gallup Poll (June 11-17, 2001) interviewed a random sample of 1009 adults (18 years or older). The people in the sample were asked how they would rate economic conditions in the United States today. Here are the results.

Outcome		Probability
Excellent		0.09
Good		0.31
Fair		?
Poor		0.16
No opinion		0.09

These proportions are probabilities for the random phenomenon of choosing an adult at random and asking the person's opinion on current economic conditions.

(a) What must be the probability that the person chosen says "fair"?

(b) The official press release focused on the percent of adults giving the economy a "positive" rating where positive is defined as "good" or "excellent." What is this probability?

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5. –/1 points MBusStat1 5.E.058. My Notes

Functional Robotics Corporation buys electrical controllers from a Japanese supplier. The company's treasurer thinks that there is probability 0.3 that the dollar will fall in value against the Japanese yen in the next month. The treasurer also believes that if the dollar falls there is probability 0.5 that the supplier will demand renegotiation of the contract. What probability has the treasurer assigned to the event that the dollar falls and the supplier demands renegotiation?

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1	2	3	4	5	6
–/1	–/1	–/1	–/1	–/1	–/1
0/50	0/50	0/50	0/50	0/50	0/50

1	2
–/1	–/1
0/50	0/50

1	2
1/1	1/1
1/50	1/50

1	2
–/1	–/1
0/50	0/50

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Moore et al-The Practice of Business Statistics (Homework)

Current Score : 2 / 13

Due : Sunday, January 27, 2030 23:30 EST

Last Saved : n/a Saving... ()

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Assignment Submission

Assignment Scoring