Answer
a) The intervals when the function is increasing are about [0, 30), and (33, 65].
The interval when the function is decreasing is about (30,33).
b) One or a couple of extreme circumstances happened in his o her life which led to a weight loss.
c) The net change is +100 lb from age 10 to age 20.
Work Step by Step
a) A function decreases when the slope is negative. While a function increases when the slope is positive.
b) Since 160 lb is a normal weight for a person and he or she lost about 40 lb in a short period of time, this person had to have gone through one or several big changes in his or her life, including famine, having no money to buy food, going through a diet, or disease.
c) d) First, we find both values which will be $P(10)≈50$ lb and $P(20)≈150$ lb, then we subtract the first one from the second one: $P(20)−P(10)=150−50=+100$ lb. The answer is positive since the person increased weight from age 10 to age 20.
