Explanation for Question 9 From the Math (Calc) Section on the 2020 March Sat
So number nine says that based on the 2010 us census, 2 the population of Milwaukee was 96% of the population of Baltimore, 3 right? So we have the population of Milwaukee, 4 which is, and we have the population of Baltimore and Milwaukee was 96% 5 of Baltimore. So we can think about Milwaukee as being 0.9, 6 six times the population of Baltimore, 7 right? And then it tells us that Milwaukee's population was five, 8 nine, 5,000, 9 which of the following is the best approximation of Baltimore's population. 10 And so we have this variable B here, 11 which we're going to solve for, to solve for Baltimore's population. 12 But basically the hardest part of this problem is coming up with this equation 13 right here, finding the way to relate the two variables. 14 But once we do that, once we see that 96% of Baltimore 15 is Milwaukee and we plug in our numbers, we can do five, 16 nine, 5,000 divided by 0.96. 17 And that will give us about six hundred and nineteen seven ninety one as 18 the population of Baltimore, which is going to be closest to answer 19 choice a and so our best answer for a number nine is going to 20 be a, and a good way to check this is that we know that, 21 um, Baltimore should be greater than Milwaukee, 22 right? So we don't want a D to be our answer. 23 We also don't want C to be our answer. And additionally, 24 we don't want B to be our answer, right? Because a is the only 25 answer that shows that Baltimore was greater than Milwaukee. 26 So even without the math, we could arrive at answer choice a just by 27 knowing that Baltimore must be greater. But if you want to get an exact 28 answer, the key is to come up with this equation right here.