Dave’s Giveaway Store advertises, “If our average prices are not equal or lower than everyone else’s, you get free.” One of Dave’s customers came into the store one day and threw counter bills of sale for six items she bought from a competitor for an average prices less than Dave’s.
The items cost
| $1.29 | $2.97 | $3.49 | $5.00 | $7.50 | $10.95 |
Dave's prices for the same six items are $1.35, $2.89, $3.19, $4.98, $7.59, and $11.50. Dave told the customer, "My ad refers to a weighted average prices of these items. Our average is lower because our sales of these items have been:
| 7 | 9 | 12 | 8 | 6 | 3 |
Is Dave getting himself into or out of trouble by talking about weighted averages?
Solution
