Violet is a biologist who has a grant to study the salmon population in northwest Washington state over the course of 400 days. Below is the graph of the the rate of change S'(d) of the population, where S is measured in hundreds of salmon and d is measured in days. hundreds of salmon per day 3 225 250 275 325 360 375 1. According to the graph. (dydd = -75. What are the units of the -75? 2. On day 250, the salmon population is 85,000; that is, S(250) = 850. Use the fact that S'(d)dd=-75 to make a prediction about the value of S(300). 3. [Reach] Write two calculus expressions using integrals converting the following sentence into math language. "There is no difference in the salmon population if Violet makes an observation on day 325 instead of day 275. but there will be a net positive change in the salmon population if she observes the population on day 350 instead of day 275."