Difficult# Cereal Boxes

APSTAT-DYILKT

A spokesman for a large cereal company is interested in whether a new promotion of including a toy in every box of cereal would greatly increase sales.

He figures that age would be a factor, so he selects one pair of subjects at each age range from $10$ to $79$ by increments of $5$ years.

The spokesman flips a coin to decide which of the pair gets a coupon for a free prize every time they buy a box of the cereal. After one year, each subject is asked how many boxes of that brand of cereal they bought. The data is in the table below:

Age Range | 10- 14 | 15- 19 | 20- 24 | 24- 29 | 30- 34 | 35- 39 | 40- 44 | 45- 49 | 50- 54 | 55- 59 | 60- 64 | 65- 69 | 70- 74 |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|

With Coupon | 9 | 8 | 8 | 5 | 4 | 12 | 14 | 13 | 8 | 6 | 5 | 4 | 4 |

Without Coupon | 7 | 4 | 8 | 6 | 5 | 7 | 8 | 7 | 6 | 6 | 4 | 3 | 4 |

From this data, is there convincing statistical evidence that people buy more cereal when a prize coupon is included?