A carpenter is trying to determine how much insulation should be put into a ceiling. The higher the R rating of the insulation, the better the insulation. The choices are limited to either R-11 or R-19 insulation. The R-11 insulation costs $0.10 per square foot while the R-19 costs $0.15 per square foot. The annual saving in heating and cooling costs is estimated to be $25 per year greater with R-19 than with R-11. If the house has 2,500 square feet and the owner expects to keep the house for 25 years, which insulation should be installed at an interest rate of 10%? Use the annual equivalent method.