<p>(94)Studies in restaurants show that the tips left by customers who pay their bill in<br />
cash tend to be larger when the bill is presented on a tray that bears a credit-card<br />
logo. Consumer psychologists hypothesize that simply seeing a credit-card logo<br />
makes many credit-card holders willing to spend more because it reminds them<br />
that their spending power exceeds the cash they have immediately available.<br />
Which of the following, if true, most strongly supports the psychologists&rsquo;<br />
interpretation of the studies?</p>
