The characteristic of geometric sequences is that any term divided by the previous term is a constant, called the common ratio. Each term in this sequence is 2 times the previous term. In this case the sequence is an=2(2)^x.
If it were an arithmetic sequence any term subtracted by the previous term would be constant, called the common difference.
Y=3.25x should be the most probable choice because 6.50 is the price of 2 pounds of candy and once it’s divided by 2 the equation will show how much the unit rate is or the price of each pound of candy.