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