A marketing firm is tasked with determining the zip codes of fans who attend a specific sporting event. The firm decides to ask fans who are coming into the event by randomly selecting a number between 1 and k, and including each kth person in their sample. What type of sampling method is used by the marketing firm in this example?
Read DetailsWhich of the following are true statements? I. Voluntary response samples often under-represent people with strong opinions. II. Convenience samples often lead to under-coverage bias. III. Surveys with confusing wording are likely to have response bias. I and II I and III II and III I, II, and III
Read DetailsIn a certain industry, 15 percent of the workers showed some signs of ill effects due to radiation. After management claimed that improvements had been made, 23 of 140 workers tested experiences some ill effects due to radiation. Use a 0.01 level of significance to conduct a test to determine if in fact the managements improvement claims are correct. Show all work for full credit. a. State the null and alternate hypotheses. b. Compute the test statistic. c. Find the critical value and/or the p value. d. Make a decision and justify it using the critical value and/or the p-value. e. Record an appropriate conclusion in context of this problem.
Read DetailsIn order to assess the effects of exercise on reducing cholesterol, a researcher sampled 50 people from a local gym who exercised regularly and 50 people from the surrounding community who did not exercise regularly. They each reported to a clinic to have their cholesterol measured. The subjects were unaware of the purpose of the study, and the technician measuring the cholesterol was not aware of whether subjects exercised regularly or not.
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