If you are reading this in an email you received from me, do not click the link to sat.collegeboard.org below. Use the link to my website that is farther down on the email. If you are seeing this in my blog, do the SAT Question of the Day by clicking on this link:
http://sat.collegeboard.org/practice/sat-question-of-the-day?src=R&questionId=20130504 (This link takes you to today’s question. If you use my archive, you will see the question related to my SAT explanation for that date.)
The answer is D. Read the SAT explanation and you will see the “math teacher” explanation which saves me a lot of typing!
I used the fact that the slopes between the different pairs of points to figure out that the graph is not a straight line. Then I used what I know about graphs in combination with the fact that based on the question I knew four of the answers are true; one isn’t. For example, if a graph is a parabola (E), it has to be “symmetric with respect to a line” (C). Similarly A and B could be correct which left answer D. However, I’m not all too happy with picking it even though I knew it had to be the correct answer!
Aren’t all functions lines? That makes D true! I explored the Internet just to make sure I wasn’t forgetting something and found all kinds of examples of graphs being lines that aren’t “straight” lines. So, the graph of the points “is a line” just like answer D states. The tricky test writers needed to put “straight” in their answer so that it would be clear what they meant. No wonder less than 40% of the students doing this question are getting it right.
Let’s move on and hope the ACT folks aren’t being this nasty.
http://www.act.org/qotd/ (The ACT staff does not put a date on their questions so if you click on an archived blog, you’ll get today’s question and the old explanation. Sorry. The SAT staff has dated their questions; so, the archive is helpful. The ACT folks simply don’t do that.)
The answer is B. This is further evidence that you shouldn’t worry about reviewing science knowledge for the test or worry that you haven’t taken the proper courses. The test is all about reading graphs (straight and curved lines :-)) and interpreting data. Among the skills on DVD #10, in my student manual, and on my website that I discuss is “extrapolation.” You will sometimes need to “extend a graph” beyond the data set that is shown on the graph, extrapolation. That’s what this question requires you to do.
You can see the trend for pH is to drop .5 for each 5 cm of depth. Three more data points (of 5 cm each) would get you to 35 cm. So, drop the pH .5 three more times. That will get you to 3.5, Answer B.
Take the time to warm up this morning while you are eating breakfast and having somebody drive you to the test center. Refer to my blogs from earlier in the week for the proper diet and how to warm up before the test. I hope things go well if you are taking the SAT this morning. Let me know how it goes.