According to an NCR white paper, it can probably be concluded that most cashiers at high-volume stores receive little or no training on how to properly scan items. What little cashier training is done is typically focused on operating the point-of-sale terminal (register),while the scanner is overlooked. The common perception is that the scanner is intuitive—a cashier passes a product in front of the scanner, the scanner beeps, and the item is successfully scanned. It turns out that scanning techniques can matter. First of all, as scanning became more prevalent, there was a rise in the number of cases of carpal tunnel syndrome (CTS) due to the way in which scanned items were handled. NCR has developed a “power slide” technique; when cashiers receive training in this method, it helps reduce CTS cases and cuts down the time required to scan each item, thereby increasing the number of items scanned per hour. In general, does this scanning training significantly increase the number of items scanned per hour? Suppose the following data are from an experiment in which a supermarket selected 14 of its best cashiers, gave them the NCR training, and measured their productivity both before and after the training. The data show the number of items checked per hour by each cashier both before and after the training. Use a Wilcoxon matched-pairs signed rank test and α = 0.05 to test the difference. Assume the underlying distributions are symmetrical.

Transcribed Image Text:

Checker 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Before 426 387 410 506 411 398 427 449 407 438 418 482 512 402 After 473 446 421 510 465 409 414 459 502 439 456 499 517 437