360 Part 4: Hypothesis Testing current machines is about due for replacement and, if the Evaluating the Cromwell model, Ted measures the exact Cromwell model is really faster, he will buy the Cromwell time required for each racquet in separate samples consist to replace it. It's possible that Cromwell models would also ing of 40 racquetball racquets and 40 tennis racquets. The be purchased as other stringing machines approach the end times are given here and are also in data file THORN10. of their operating lifetimes and are retired. Luke cautions Since Luke seems quite adamant against buying some- Ted that the Cromwell must be purchased only if it is in- thing that isn't any faster than the current models, Ted deed faster than the current models-although Ms. Scott must be very confident that any increased speeds mea- seems to have an honest face, he's never trusted anybody sured are not simply due to chance. Using a computer whose briefcase contains brochures. The Cromwell must statistical package to analyze the sample times, do the re- be quicker in stringing both racquetball racquets and ten spective tests appear to warrant purchase of the Cromwell nis racquets. Otherwise, the firm will continue purchasing machine, or should it be returned to Cromwell at the end and using the current model. of the week? 40 Racquetball Racquets: 40 Tennis Racquets: 2.97 3.43 3.10 2.79 3.41 3.22 3.36 3.46 3.77 3.97 4.08 4.36 3.85 4.65 3.89 3.99 3.11 3.26 3.36 3.48 3.09 3.06 2.67 3.13 3.51 3.43 4.31 3.84 3.86 3.50 4.23 3.88 2.97 3.09 3.18 2.71 3.41 2.83 3.20 3.32 3.91 4.47 4.27 3.70 3.80 4.54 4.46 3.97 2.70 3.17 3.16 3.16 3.24 2.91 3.34 2.97 4.49 3.74 4.17 3.68 4.09 427 3.84 3.51 3.14 3.36 3.89 3.21 3.13 2.92 2.94 3.18 3.71 3.77 3.90 4.14 4.03 4.61 3.63 462 minutes minutes Www odlete Using a computer statistical package to analyze the sample times, do the re-spective tests appear to warrant purchase of the Cromwell machine, or should it be returned to Cromwell at the end of the week? 360 Part 4: Hypothesis Testing current machines is about due for replacement and, if the Evaluating the Cromwell model, Ted measures the exact Cromwell model is really faster, he will buy the Cromwell time required for each racquet in separate samples consist to replace it. It's possible that Cromwell models would also ing of 40 racquetball racquets and 40 tennis racquets. The be purchased as other stringing machines approach the end times are given here and are also in data file THORN10. of their operating lifetimes and are retired. Luke cautions Since Luke seems quite adamant against buying some- Ted that the Cromwell must be purchased only if it is in- thing that isn't any faster than the current models, Ted deed faster than the current models-although Ms. Scott must be very confident that any increased speeds mea- seems to have an honest face, he's never trusted anybody sured are not simply due to chance. Using a computer whose briefcase contains brochures. The Cromwell must statistical package to analyze the sample times, do the re- be quicker in stringing both racquetball racquets and ten spective tests appear to warrant purchase of the Cromwell nis racquets. Otherwise, the firm will continue purchasing machine, or should it be returned to Cromwell at the end and using the current model. of the week? 40 Racquetball Racquets: 40 Tennis Racquets: 2.97 3.43 3.10 2.79 3.41 3.22 3.36 3.46 3.77 3.97 4.08 4.36 3.85 4.65 3.89 3.99 3.11 3.26 3.36 3.48 3.09 3.06 2.67 3.13 3.51 3.43 4.31 3.84 3.86 3.50 4.23 3.88 2.97 3.09 3.18 2.71 3.41 2.83 3.20 3.32 3.91 4.47 4.27 3.70 3.80 4.54 4.46 3.97 2.70 3.17 3.16 3.16 3.24 2.91 3.34 2.97 4.49 3.74 4.17 3.68 4.09 427 3.84 3.51 3.14 3.36 3.89 3.21 3.13 2.92 2.94 3.18 3.71 3.77 3.90 4.14 4.03 4.61 3.63 462 minutes minutes Www odlete Using a computer statistical package to analyze the sample times, do the re-spective tests appear to warrant purchase of the Cromwell machine, or should it be returned to Cromwell at the end of the week