The data in which of the following scatterplots would be best modeled by a quadratic function in which the `x^(2)` term has a negative coefficient?

Options

A.
B.
C.
D.

Answer

D

Explanation

Difficult: Easy
Category: Problem Solving and Data Analysis/ Scatterplots
Strategic Advice: Data that can be modeled by a quadratic function should take the shape of a parabola (or part of a parabola), which looks like a U. Part of the data should increase from left to right, and part of the data should decrease (at some point, the data turns around)
Getting to the Answer: The data in choice A follows a linear pattern, so eliminate it. The data in C is curved, but it is always decreasing (it never turns around), which means it can't be modeled by a quadratic function, so eliminate it as well. To choose between B and (D), recall that a negative coefficient on the `x^(2)` term means the parabola opens downward (because it has been reflected vertically across the x-axis). This means (D) is correct.