In a series of tests conducted to compare two CD ROM drives, storagereview.com looked at the performance of the Kenwood UCR004010 and the Plextor UltraPlex PX 32Tsi. One of the characteristics of interest was “outside transfer rate,” the rate at which the drives are able to transfer data on the outer tracks of the CD. The average outside transfer rate in the sample of trials for the Kenwood model was 6472 KB/ sec and for the Plextor the average was 4944 KB/ sec (source: storagereview.com). If each model was tested 35 times, and the standard deviations of the transfer rates were 875 KB/ sec for the Kenwood model and 1208 KB/ sec for the Plextor model,
a. Build a 99% confidence interval of the difference in average transfer rates for the two models (at the “ population” level).
b. Interpret the interval.