Aurgh!! I'm so angry! Stupid engineering economics, the most stupid course in my entire university career. Why can't economists do things like normal people? I'm an engineer, our whole class is engineers, we've been trained to go through derivations, understand formulas, and use formulas. Now, why are we forced to deal with the 'look it up in the table' crap in this course? This is the method that people used to solve problems before they had computers and calculators. Believe me, the formulas aren't that difficult, I've had to use far worse in other courses. The problem with the tables is that they only cover a finite number of possibilities. To find an answer in between two table values, I'm forced to extrapolate, therefore greatly decreasing the accuracy of my answer. And then we have the cases where the table doesn't cover them at all. Most of the tables cover up to a certain number of interest periods, around 100. Then I had a question that gave me 240 interest periods. In the answers, it told me I should use the formula. If I'm going to have to use the formula anyways, WHY do you INSIST on making me use the stupid table method for the other questions?!? WHAT IS WRONG WITH YOU PEOPLE????