<p>I just did the sample cb questions and I have a question regarding number 29, which if any of you may recall is the one that provides you with a small table of x and y values and ask you to pick the most suitable graph. I was wondering whether the best way to do this would be to enter into the calculator and do the regression or if there was another way.</p>
<p>The link is below(off the collegeboard site number 29 on math 2 sample questions thanks):</p>
<p>bump and plz can anyone tell me if we have to know any regression for the test?
thanks</p>
<p>The most straightforward approach seems to be plugging in x's into each f(x) and seeing which comes closest to the y's. If you're fast, shouldn't take more than 30 seconds.</p>
<p>As for regression, it's calculator friendly. I figured this out today. Regression problems usually have a table of data, and ask you some value for a certain independent variable.</p>
<p>Ex. A company's annual income increases for each year after it has been opened. The number of years after opening and the new income is represented in a table. (made up problem, the values probably are skewed)</p>
<p>1 4 7 (years)
1000 2500 8000 (dollars)</p>
<p>Based on a least squares exponential regression, what is the expected income 9 years after opening?</p>
<p>Type:
{1, 4, 7}
sto
2nd 1 (aka L1)
enter
{1000, 2500, 8000}
sto
2nd 2 (aka L2)
enter
STAT
CALC
ExpReg
L1, L2
enter</p>
<p>You get an equation in the form y = ab^x with a and b given to you. Plug in 9 for x and you're done.</p>
<p>That easy.</p>
<p>Thanks James for the regression thing never knew that, will we ever need that on the math part? I mean we could just plug in numbers or for this problem, you can easily tell A/B not right since the whole things turns negative with positive x-values and then C and E are HUGE numbers because 3^8 or 8^3 is huge.</p>
<p>Regression will probably pop up for one question. You're right about eliminating choices by sight. I didn't look at the problem that closely.</p>