Question 1 is pretty straightforward. We assume metabolic rate in Watts equals body mass in grams, so the hippo has a mass of 1 million grams, so it would have a metabolic rate of 1 million Watts. Easy enough. Ok, part 2, says what if we assume that metabolic rate equals body mass raised to the 2/3 power. One million raised to the 2/3, it is easy to see if you know something about the way exponents work, that it's equal to 10 thousand Watts. But, let's look and see how to do this using Google. Here I am at the Google window, I am going to type in 1000000, which is 1 with 6 0's raised to the 2/3's. I get the calculator and it tells me that it is 10000. Ok, same as question 1, but assume that metabolic rate is equal to body mass to the 3/4, again I used Google for this and got approximately 31, 623.