A dozen eggs cost $0.88 in January 1980 and $2.11 in January 2015. The average wage for production workers was $7.58 per hour in January 1980 and $19.64 in January 2015.
a. By what percentage did the price of eggs rise?
b. By what percentage did the wage rise?
c. In each year, how many minutes did a worker have to work to earn enough to buy a dozen eggs?
d. Did workers' purchasing power in terms of eggs rise or fall?