Answer Choices
s1 = s2 and r1 = r2
s1 < s2 and r1 < r2
s1 > s2 and r1 > r2
s1 not s2 and r1 = r2
Explanation for Question 28 From the Math (Calc) Section on the Official Sat Practice Test 8
So question 28 shows us the distribution of students in a health class. 2 And we see in our first set of data that it's shaped kind of 3 like a bell curve. Whereas our second set of data is more evenly distributed, 4 right? And so here we're asked to compare the ranges and the standard deviation 5 of the data. And so it's probably likely that you're more familiar with the 6 concept of range, the difference between the largest value and 7 the smallest value. So if we focus on range first, 8 we can see that the difference between 88 and 56 is 32. 9 So our first set of data has a range of 32 and the difference 10 between 112 and 80 is also 32. 11 So our ranges are equal. And for that reason, 12 we can eliminate answer choices, B and C, and this makes our lives a 13 little easier because when we think about standard deviation, 14 we are not going to try to figure out whether one is larger or 15 one is smaller, but rather whether they're equal or if they're not equal. 16 And so it's possible that you've learned how to calculate standard deviation, 17 but for the sat, you don't need to know how to calculate it, 18 but more so, what it means, and standard deviation is a measure of spread 19 as a measure of variation around the mean value. 20 And for both of these datasets, we know that the mean value is going 21 to occur somewhere in the middle, right? But if we look at our first 22 data set, our data points are more so clustered towards the middle. 23 So our data points are more cl...