Haha, I suppose you belong to the old school of thought when this was still even an issue. I belong to the newer school of thought when you work out all the variables first and then insert all the values into the final equation to crank out the answer all at once. In other words, there's no such thing as an intermediate calculation, just like there's no such thing as an intermediate evolutionary step. Hey, I just realized something. Are you a creationist trapped inside an evilutionist body?
By the way, you're right. I just glanced through it and thought he was talking about the final answer. Yes, if it was an intermediate calculation, he should have used 39.2. I guess there's always a first time I could be wrong
Everyone should be required to learn how to use a graphing calculator nowadays.