Select the correct answer.

Which equation best models the set of data in this table?

\begin{tabular}{|c|c|c|c|c|c|c|c|c|c|c|}
\hline
[tex]$x$[/tex] & 0 & 1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 & 9 \\
\hline
[tex]$y$[/tex] & 32 & 67 & 79 & 91 & 98 & 106 & 114 & 120 & 126 & 132 \\
\hline
\end{tabular}

A. [tex]$y = 33x - 32.7$[/tex]
B. [tex]$y = 33x + 32.7$[/tex]
C. [tex]$y = 33 \sqrt{x - 32.7}$[/tex]
D. [tex]$y = 33 \sqrt{x} + 32.7$[/tex]



Answer :

To determine which equation best models the given set of data, we will perform the following steps:

1. Calculate the linear regression line:

First, we need to find the best fit line in the form \( y = mx + b \) where \( m \) is the slope and \( b \) is the y-intercept.

Given:
[tex]\[ x = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] \][/tex]
[tex]\[ y = [32, 67, 79, 91, 98, 106, 114, 120, 126, 132] \][/tex]

The calculated slope \( m \) and y-intercept \( b \) are:
[tex]\[ m = 9.67 \quad \text{(approximately)} \quad \text{and} \quad b = 53.00 \quad \text{(approximately)} \][/tex]

So, the best fit line is:
[tex]\[ y = 9.67x + 53.00 \][/tex]

2. Generate y-values based on the regression line:

Using the equation \( y = 9.67x + 53.00 \), the predicted \( y \)-values are:

[tex]\[ [53, 62.67, 72.33, 82, 91.67, 101.33, 111, 120.67, 130.33, 140] \][/tex]

3. Calculate the error term for each given equation:

We will use the sum of the squared errors (SSE) to determine how well each given equation fits the data. The equation with the smallest SSE will be the best fit.

[tex]\[ \text{Error} = \sum_{i=1}^{n} (y_{\text{actual},i} - y_{\text{predicted},i})^2 \][/tex]

Given options are:
- Option A: \( y = 33x - 32.7 \)
- Option B: \( y = 33x + 32.7 \)
- Option C: \( y = 33 \sqrt{x - 32.7} \)
- Option D: \( y = 33 \sqrt{x} + 32.7 \)

Calculated errors for each of these options:
- Error A: 49380.90
- Error B: 117396.90
- Error C: \( \text{(undefined due to square root of a negative number)} \)
- Error D: 4.66

4. Identify the best fit option:

From the errors calculated, we find that the equation with the smallest error is option D. This indicates that option D fits the given data set best.

Therefore, the equation that best models the given set of data is:

[tex]\[ \boxed{y = 33 \sqrt{x} + 32.7} \][/tex]