Answer to Question #44851 in Statistics and Probability for venotini

Question

A number of restaurants feature a device that allows credit card users to swipe their cards at the table. It allows the user to specify a percentage or a dollar amount to leave as a tip. In an experiment to see how it works, a random sample of credit card users was drawn. Some paid the usual way, and some used the new device. The percent left as a tip was recorded and listed below. Can we infer that users of the device leave larger tips?

Usual: 10.3 15.2 13.0 9.9 12.1 13.4 12.2 14.9 13.2 12.0
Device: 13.6 15.7 12.9 13.2 12.9 13.4 12.1 13.9 15.7 15.4 17.4