[Video] Q13: The population of mosquitoes in a swamp is estimated over the course of twenty weeks, as shown in the table. which of the following best describes the relationship between time and the estimated population of mosquitoes during the twenty weeks?

Explanation for Question 13 From the Math (Calc) Section on the Official Sat Practice Test 4

Now here in number 13, we're looking at a population of mosquitoes over a 2 time period. Right. And we need to figure out which relationship best shows the 3 estimated time period over the weeks. 4 Right? And so we can see that we have a plus five weeks from 5 here to here. If we go up five weeks from here to here, 6 essentially we're jumping up five each time. 7 So our change in time is constant, 8 right? Five weeks. However, 9 the change in population, oops, here we went up plus 900. 10 This time we went up plus 9,000. 11 This time we went up 90,000 and this time we went up 900,000. 12 So even though our change in X is constant, our change in Y is 13 not constant. And something that's important to know is that constant is 14 basically the same thing as linear. 15 So since we're not constant, that means we're not linear. 16 So we can't be a or B. Right. 17 We're actually exponential because each time we're really just multiplying by 10. 18 And when you're changing by multiplication, rather than addition, 19 that shows you exponential growth, 20 right? And so this, this part is easier growth or decay. 21 We see that we got bigger over time. So that indicates growth, 22 um, making our best answer, uh, answer choice C.