Low-energy lightbulbs typically cost $3.70, have a life of nine years, and use about $1.80 of electricty a year. Conventional lighibulbs are cheaper to buy, for they cost only $.54 On the other hand, they last only about a year and use about $6 80 of energy a. If the real discount rate is 5 %, what is the equivalent annual cost of the two products? (Do not round intermediate calculations. Enter your answers as a positive value rounded to 2 decimal places.) Equivalent Annual Cost Low-energy lightbulbs Conventional lightbulbs b. Which product is cheaper to use?" Low energy lightbulbs Conventional lightbulbs