• How do you get -3?
• 

19. Data on the prices, quantities sold and average incomes of buyers of Jolt Cola and Coke, over several years, are shown below: Average Year Price of Jolt Price of Coke Income of Quantity of Jolt Cola Buyers Sold 2010 $1.00 / can $1.00 / can $25,000 15,000 cases 2011 $1.00 / can $1.40 / can $25,000 25,000 cases 2012 $1.00 / can $1.40 / can $35,000 15,000 cases 2013 $1.40 / can $1.40 / can $35,000 5,000 cases What is the own-price elasticity of Jolt Cola? a. -3.00 b. -0.6 c. -0.33 d. -1.67 e. not determinable, since all of the variables are changing