# Question of the Day September 1 2013

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?questionId=20130901&oq=1 (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 C.  The test writers must have started reading my blog!  They usually do some complicated math to do function questions and I always explain the easy way that often doesn’t involve much math at all.  Frequently you can do function questions by just reading the graph.  This is a great example of that wizardly approach.

F(x) just means y on the graph when x is is a certain amount.   So, pick a point on the graph and follow my strategy for all math questions: What did the test writers tell me and what do I know because they told me that?  In this case, they tell you that  f(x) or y is -5 when x=0.  Then they tell you that g(x) is a new value for y when you add 4 to the original y=-5.  Adding 4 to -5 gives us -1.  Just slide in your mind (or draw if you need to) the exact same graph up on the scale +4 so that the low point on the graph is at -1.  Then the graph still has to go through the x-axis twice and that is where the new graph is y=0.  Shazaam–all done!!!

I wonder what the ACT folks have in store for us today.

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, their archive is helpful. The ACT folks simply don’t do that.)

The answer is H.  As always on the ACT, reviewing science content is a waste of time.  Don’t worry about what science topics you’ll see on the test; you’ll never predict them.  You need to focus on practicing graph and chart reading along with how to do science research and interpreting data.  This is a perfect example of what you see and need to do on test day.

First, make sure you are reading the right graph or figure.  They tell you where to look but you’ll be in a hurry and may get lost.  This question tells you “Figure 3”.  Be sure that’s where you go.

Second they tell you 150 years; so, scan across the x-coordinate to 150 years.  Oops, they don’t tell you 150 but you can see that it is between 110 and 200 but a  little closer to 110.  Go straight up there to the dotted, oak-hickory line.  That line is at about 15,000.  There’s the answer, H.

“Reading between the data points” is called interpolation and you’ll need to do it on the ACT.  There’s more about interpolation and its buddy “extrapolation” in your textbooks, on the internet, and in my materials.  Check out “Demystifying the SAT and ACT” and Video #10.  They will be a big help.

Enjoy your day off school.  I’m going to be at the beach!!

Wizard