6. For each of the scenarios below, identify the sampling blunder, speculate about the influence of the bias, and then make a recommendation for ridding the study of the biasing influence. a. A researcher wanted to know how people in the local community felt about the use of high-stakes testing in the public schools. The researcher spent the afternoon at Wal-Mart and randomly approached 100 shoppers to ask their opinion (they all agreed to cooperate). Random selection was accomplished with the use of a random number table (the numbers determined which shopper to target, such as the 16th to exit, then the 30th to exit, then the ninth to exit, etc.). b. A researcher wanted to know how students at a university felt about mandatory fees for all students to support a child care center for students with children. The researcher set up a table near the dormitory where many different types of students came and went. Those who stopped at the table and seemed friendly were asked to complete the questionnaire. c. To study differences in occupational aspirations between Catholic high school students and public high school students, a researcher randomly sampled (using school rosters and a random number table) 200 students from the largest Catholic high school and the largest public high school. d. To learn more about teachers' feelings about their personal safety while at school, a questionnaire was printed in a nationwide subscription journal of interest to many teachers. Teachers were asked to complete the questionnaire and mail it (postage paid) to the journal headquarters for tabulation. e. To study the factors that lead teachers in general to quit the profession, a group of teachers threatening to quit was extensively interviewed. The researcher obtained the group after placing an announcement about the study on the teachers' bulletin board at a large elementary school.

psychological test before and after treatment in order to determine the effectiveness of the treatment. Researchers hope to find a difference in test scores before and after treatment. A 95% CI for the population average difference in test scores (before-after) is given by (0.25, 3.75), which was computed based on a random sample of 36 patients.

a) What is the population parameter of interest? mu1? mu2? mud?

b) Based on the confidence interval, at a 5% significance level, would 0 be considered a reasonable value of the population parameter?

c) Based on the CI, what is the value of the sample statistic (point estimate)?

d) Based on the CI and the sample statistics found in c). What is the value of the standard error (SE) of the sample statistic? Hint: UB = point estimate + margin of error = Xd+E= Xd+cv X SE(Xd)

e) Is there a significant difference in test scores (before - after) on average? Perform an appropriate hypothesis test using α = 0.10.

I. List data assumptions.

II. State H0 and Ha.

III. Calculate the test statistic.

IV. Make decision using the rejection region approach.

V. Draw conclusion.

Suppose a firm buys a machine with a 4 year useful life for $280,000. The machine has a salvage value of $20,000. Do each question separately.

V. Assume the firm uses straight-line depreciation. After two years of depreciation, the firm conducts an impairment test. It concludes the net cash flows from the machine for the remaining two years will be $60,000 per year. Is the machine impaired? Record the journal entry if it is impaired. Assume that the appropriate discount rate is 4%.

VI. Assume the firm uses the units of activity depreciation method where it allocates depreciation expense proportionate to the number of hours the machine is operated. It anticipates operating the machine for 3,000; 3,200; 3,300 and 3,500 hours in the next four years, respectively. Calculate the depreciation expense and net book value for each year.

VII. A steelmaker’s assets will largely consist of tangible assets like inventories and property, plant and equipment. List a firm for which the most valuable things that the firm owns are intangible assets that are not recorded on the balance sheet. Which of the two firms (the steelmaker or the firm you selected) is likely to have the larger market to book ratio? Explain why.

CARLILL V CARBOLIC SMOKE BALL CO [1893]

IN THE 1890S, ENGLAND WAS PLAGUED BY TWO RELATED PHENOMENA: AN INFLUENZA EPIDEMIC AND QUACK MEDICINE. THE CARBOLIC SMOKE BALL CO WAS ONE OF MANY COMPANIES THAT TRIED TO CAPITALIZE ON THE COUNTRY’S ILL HEALTH. IT PRODUCED A HAND-HELD GADGET THAT, WHEN SQUEEZED, EMITTED A SMALL CLOUD OF CARBOLIC ACID DUST. THE COMPANY CLAIMED THAT IF ONE INHALED THE DUST REGULARLY, IT WOULD PREVENT A LONG LIST OF AILMENTS RANGING FROM DIPHTHERIA AND BRONCHITIS TO SNORING AND SORE EYES. AS PART OF ITS MARKETING PLOY, THE COMPANY PUBLISHED AN ADVERTISEMENT THAT OFFERED TO PAY £100 TO ANY PERSON WHO CONTRACTED INFLUENZA WHILE USING THE CARBOLIC SMOKE BALL. MRS CARLILL SAW THE AD, BOUGHT THE PRODUCT, AND USED IT AS DIRECTED. WHEN SHE LATER CAME DOWN WITH THE FLU, SHE CLAIMED TO BE ENTITLED TO £100. THE COMPANY REFUSED TO PAY. IT SAID THAT THERE WAS NO CONTRACT BECAUSE SHE HAD NOT TOLD THEM THAT SHE HAD ACCEPTED THEIR OFFER AND WAS USING THEIR PRODUCT.

Do you agree with the Court that the actions of the Company created an offer that was open to be accepted by Ms. Carlill? Do you agree with the concept of "Invitation to Treat"?

CARLILL V CARBOLIC SMOKE BALL CO [1893]

IN THE 1890S, ENGLAND WAS PLAGUED BY TWO RELATED PHENOMENA: AN INFLUENZA EPIDEMIC AND QUACK MEDICINE. THE CARBOLIC SMOKE BALL CO WAS ONE OF MANY COMPANIES THAT TRIED TO CAPITALIZE ON THE COUNTRY’S ILL HEALTH. IT PRODUCED A HAND-HELD GADGET THAT, WHEN SQUEEZED, EMITTED A SMALL CLOUD OF CARBOLIC ACID DUST. THE COMPANY CLAIMED THAT IF ONE INHALED THE DUST REGULARLY, IT WOULD PREVENT A LONG LIST OF AILMENTS RANGING FROM DIPHTHERIA AND BRONCHITIS TO SNORING AND SORE EYES. AS PART OF ITS MARKETING PLOY, THE COMPANY PUBLISHED AN ADVERTISEMENT THAT OFFERED TO PAY £100 TO ANY PERSON WHO CONTRACTED INFLUENZA WHILE USING THE CARBOLIC SMOKE BALL. MRS CARLILL SAW THE AD, BOUGHT THE PRODUCT, AND USED IT AS DIRECTED. WHEN SHE LATER CAME DOWN WITH THE FLU, SHE CLAIMED TO BE ENTITLED TO £100. THE COMPANY REFUSED TO PAY. IT SAID THAT THERE WAS NO CONTRACT BECAUSE SHE HAD NOT TOLD THEM THAT SHE HAD ACCEPTED THEIR OFFER AND WAS USING THEIR PRODUCT.

think critically about what you know of the nature of offer and acceptance. Has Mack committed a crime? What argument should Mack's lawyer make to absolve him?

Suppose that grade point averages of undergraduate students at one university have a bell-shaped distribution with a mean of 2.61 and a standard deviation of 0.39. Using the empirical rule, what percentage of the students have grade point averages that are between 1.83 and 3.39?

In a local university, 40% of the students live in the dormitories. A random sample of 80 students is selected for a particular study. The probability that the sample proportion (the proportion living in the dormitories) is at least 0.30 is

Select one:

a. 0.0336

b. 0.9664

c. 0.9328

d. 0.4664

The test scores of 40 students are summarized in the frequency table below. What is the standard deviation, mean, and median?

Score students

50-59 14

60-69 6

70-79 5

80-89 9

90-99 6

A test prep website claims that students who use their service improve their SAT scores by more than 109 points. After using the site, a random sample of 25 students improved by an average of 102 points with a standard deviation of 23.2 points.