Which of the following best models the data in the table?

Type of Function

The table presents values of x and y, showing how y increases as x increases
x y
2
8.5
4
46
6
107.5
8
193
(1 point)
Responses

cubic
cubic

linear
linear

exponential
exponential

quadratic

1 answer

To determine which type of function best models the data, we can analyze the rate of change in the values of \(y\) as \(x\) increases.

Given the pairs from the table:

  • When \(x=2\), \(y=8.5\)
  • When \(x=4\), \(y=46\)
  • When \(x=6\), \(y=107.5\)
  • When \(x=8\), \(y=193\)
  1. Linear Function: A linear function would show a constant rate of change. However, we can calculate the differences:

    • From \(y=8.5\) to \(y=46\): \(46 - 8.5 = 37.5\)
    • From \(y=46\) to \(y=107.5\): \(107.5 - 46 = 61.5\)
    • From \(y=107.5\) to \(y=193\): \(193 - 107.5 = 85.5\)

    The differences are not constant, ruling out a linear function.

  2. Quadratic Function: A quadratic function would have a second difference that is constant. Here are the first differences again:

    • First differences: \(37.5\), \(61.5\), \(85.5\)
    • Second differences:
      • \(61.5 - 37.5 = 24\)
      • \(85.5 - 61.5 = 24\)

    The second difference is consistent, suggesting that a quadratic function might be appropriate.

  3. Cubic Function and Exponential Function:

    • A cubic function would generally show a changing second difference. The second difference is consistent, so a cubic model is not suggested here.
    • An exponential function tends to grow at an increasing rate, but the values do not appear to follow an exponential growth pattern since the differences grow but in a way that aligns more with a quadratic trend.

Based on this analysis, quadratic is the most suitable type of function to model this data. Therefore, the answer is:

quadratic