Final answer:
To find the rate of change in the number of fry between 2017 and 2018, subtract the number of fry in 2017 from the number of fry in 2018 and divide by the difference in years.
Step-by-step explanation:
To find the rate of change in the number of fry between 2017 and 2018, we need to subtract the number of fry in 2017 from the number of fry in 2018 and then divide that difference by the number of years between 2017 and 2018.
Let's say the number of fry in 2017 was 1000 and the number of fry in 2018 was 1500. The difference between the two years is 1500 - 1000 = 500. Since there is a difference of 1 year between 2017 and 2018, the rate of change would be 500 fry per year.