We spent the session doing a problem in which we examined the claim that shoppers with higher denominations of cash tend to spend less than shoppers with lower denominations. (Two proportions, two samples.) We used the P-value and Critical Value methods to investigate the claim and then used a confidence interval to explore the difference between the two proportions. The evidence suggested that shoppers with higher denominations do spend less. But the sample consisted only of undergraduate students, so it would be risky to attribute this propensity to all American shoppers.