J.A. Hersh and Company provides court transcription services. The company is considering two keyboard styles for its staff to use in court. One factor that will influence its decision is the ease of use. Suppose that to test the keyboards, nine court transcribers were selected and asked to transcribe a 75-minute court hearing using each keyboard. The transcribers then rated the systems on a scale of 0 to 100. The resulting ratings are in the file Hersh.

a. Which measurement level describes the data collected for this analysis?

b. (1) Could a normal distribution describe the population distribution from which these data were sampled? (2) Which measure of central tendency would be appropriate to describe the center of the populations from which these data were sampled?

c. Choose the appropriate hypothesis-testing procedure to determine if there is a difference in the measures of central tendency you selected in part b between these two keyboards. Use a significance level of 0.01.

d. Which keyboard would you recommend the Hersh Corporation adopt? Support your answer with statistical reasoning.