Explanation for Question 15 From the Math (Calc) Section on the 2019 March Sat
Question 15 says a park ranger asked a random sample of visitors, 2 how far they hiked during their visit. Based on the responses, 3 the estimated mean was found to be 4.5 miles within associated margin 4 of error of 0.5 miles, which of the following is the best conclusion from 5 these data. So the first thing we need to know from this answer is 6 that the estimated mean is 4.5 miles. 7 And the margin of error is your 0.5 miles. 8 That means that based on the responses, the mean that they calculated might've been 9 incorrect. It could have been 0.5 less than 4.5 or 0.5 10 more. Which means that the mean is somewhere between four and five. 11 Now, since a mean is just the average of all of the survey responses. 12 It's not what everyone answered or what some people answered, 13 what was average together. We can now figure out what the answer is here. 14 So it is likely that all visitors hiked between four and five miles. 15 Um, it's possible. So we're going to keep this one open for now. 16 B says it is likely that most visitors hiked exactly 4.5 miles. 17 That's not likely, uh, because this data is telling us that the mean was 18 between four and five miles. Not even that it was exactly 4.5 miles. 19 So B is incorrect. C says it is not possible 20 that any visitor high to less than three miles. 21 Um, and that's not true. Amine is, 22 again, just an average of all the data. There could have been outliers. 23 There could have been someone who hiked to 0.5 miles and some like 1...