Discussion:
Q1: At Oxnard University, a sample of 25 senior accounting majors showed a mean cumulative GPA of 3.25 with a standard deviation of 0.10. At α= .05 in a two-tailed test, does this differ significantly from 3.20 (the mean GPA for all business school seniors at the university)?
Q2: Faced with rising fax costs, a firm issued a guideline that any transmission of 10 pages or more should be sent by 2-day mail instead. Exceptions are allowed, but they want the average to be 10 or below. The firm examined 81 randomly chosen fax transmissions during the next year, yielding a sample mean of 10.2 with a standard deviation of 1.1 pages. At the .05 level of significance, is the true mean greater than 10? Explain your decision.
Q3: The Web-based company Oh Baby! Gifts have a goal of processing 95 percent of its orders on the same day they are received. If 585 out of the next 600 orders are processed on the same day, would this prove that they are significantly exceeding their goal, using α = .01? Explain your decision.