A company is considering purchausing an impact wrench for $1000 which wich has a maximum life of 4 years. The impact wrench can be sold for $600 at the end of oneyear and this salvage value decreases by $200 per year through year 4. The operational and maintenance cost for this wrench is $100 during year 1, $225 in year 2, $350 in year 3 and is $400 in year 4. Using tabular approach find the economic life of the wrench. The company has an annual i = 20%