Explanation for Question 15 From the Math (Calc) Section on the 2017 May Sat
Question 15 and 16, um, 2 are connected, but let's first look at question 15. 3 It says a wildlife biologist uses the formula above, 4 which is age equals three C to estimate the height age in 5 centimeters of an elephant from its foot to its shoulder, 6 based on the circumference, the sea and centimeters of the elephant's footprint. 7 So what we shouldn't be picking up from there is that, 8 um, age is the height and C 9 is a circumference. So now let's look at question 15. 10 It says if the wildlife biologist finds a circular elephant footprint that has a 11 diameter of 30 centimeters while in a psychological study, 12 which of the following is closest to the biological biologists estimate of the elephant's 13 height. So we're looking for the height. 14 So we know we're looking for age, but we don't quite have see yet. 15 They give us diameter. And have you remember, 16 there's a formula for diameter that relates to circumference, 17 which says circumference equals to D times PI. 18 So if we know that diameter is 30, 19 we can just replace it there and we can get that C 20 equals 30 PI. Now we just plug that into 21 our formula above here, and we get H 22 equals three times 30 23 PI, and we are allowed to use our calculator looking at our answer choices. 24 We do see that they multiply PI in. 25 You can use 3.14, four PI, 26 or if you have a calculator that hotspot you can provide, 27 um, but we're going to use 2.14. So we do 30 times 3.14, 28 and we multiply that by three, 29 which gives us 282.6 or D.