What factors inhibit the learning process in the classroom? To answer this question, researchers at Murray State University surveyed 40 students from a senior-level marketing class (Marketing Education Review, Fall 1994).

Each student was given a list of factors and asked to rate the extent to which each factor inhibited the learning process in courses offered in their department. A 7-point rating scale was used, where I = "not at all" and 7 =

"to a great extent."The factor with the highest rating was instructor-related: "Professors who place too much emphasis on a single right answer rather than overall thinking and creative ideas." Summary statistics for the student ratings of this factor are: i = 4.70, s = 1.62.

a. Conduct a test to determine if the true mean rating for this instructor-related factor exceeds 4. Use a = .05. Interpret the test results

b. Because the variable of interest, rating, is measured on a 7-point scale, it is unlikely that the population of ratings will be normally distributed. Consequently, some analysts may perceive the test, part

a, to be invalid and scarch for alternative methods of analysis.
Defend or refute this argument.
Current technology uses X-rays and lasers for inspection of solder-joint defects on printed circuit boards (PCBs) (Quality Congress Transactions, 1986). A particular manufacturer of laser-based inspection equipment claims that its product can inspect on average at least 10 solder joints per second when the joints are spaced .1 inch apart. The equipment was tested by a potential buyer on 48 different PCBs. In each case, the equipment was operated for exactly 1 second. The number of solder joints inspected on each run follows:

a. The potential buyer wants to know whether the sample data refute the manufacturer's claim. Specify the null and alternative hypotheses that the buyer should test.

b. In the context of this exercise, what is aType I error?
A Type I1 error?

c. Conduct the hypothesis test you described in part

a, and mterpret the test's results in the context of this exercise. Use a = .05 and the SPSS descriptive statistics printout at the bottom of the page.