Question 1114588
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In all four answer choices, the x values are equally spaced; this makes it relatively easy to find the answer to the question.<br>
One way to find the answer is knowing that, in a quadratic function, the graph has an axis of symmetry; the y values are symmetrical.  In choice D, the y values are 14, 2, -2, 2, and 14.  So<br>
Answer:  data set D<br>
A more advanced way of recognizing quadratic data is that, as long as the x values are equally spaced, the second differences in the y values are constant.<br>
For answer choice D, the first differences in the sequence of y values are -12, -4, 4, and 12; the second differences are 8, 8, and 8.  That constant second difference tells us the data is quadratic.<br>
None of the other data sets has a constant second difference in the y values, so answer choice D is the only quadratic set of data.