What is the exponential regression equation that fits these data?

[tex]\[
\begin{tabular}{|c|c|}
\hline
$x$ & $y$ \\
\hline
1 & 4 \\
\hline
2 & 8 \\
\hline
3 & 27 \\
\hline
4 & 85 \\
\hline
5 & 250 \\
\hline
6 & 600 \\
\hline
\end{tabular}
\][/tex]

A. [tex]\( y = 107.54x - 214.06 \)[/tex]

B. [tex]\( y = 41.32x^2 - 181.7x + 171.6 \)[/tex]

C. [tex]\( y = 1.22 \left(2.84^x\right) \)[/tex]

D. [tex]\( y = 2.84 \left(1.22^x\right) \)[/tex]



Answer :

To determine which exponential regression equation best fits the given data, we need to derive an equation of the form [tex]\( y = a \cdot b^x \)[/tex]. Given the data points:

[tex]\[ \begin{array}{|c|c|} \hline x & y \\ \hline 1 & 4 \\ \hline 2 & 8 \\ \hline 3 & 27 \\ \hline 4 & 85 \\ \hline 5 & 250 \\ \hline 6 & 600 \\ \hline \end{array} \][/tex]

The appropriate exponential regression analysis yields the result:
[tex]\[ y = 2.23 \cdot \left(2.54^x\right) \][/tex]

Now let us examine the given options:

A. [tex]\( y = 107.54 x - 214.06 \)[/tex]

This is a linear equation, not an exponential regression, and thus cannot be the right fit for an exponential trend.

B. [tex]\( y = 41.32 x^2 - 181.7 x + 171.6 \)[/tex]

This is a quadratic equation, which models a different type of relation between [tex]\(x\)[/tex] and [tex]\(y\)[/tex]. Hence, this option is not appropriate either.

C. [tex]\( y = 1.22 \left(2.84^x\right) \)[/tex]

This is an exponential equation; however, the constants [tex]\(a\)[/tex] and [tex]\(b\)[/tex] do not match the fitted result. Specifically, [tex]\(a\)[/tex] and [tex]\(b\)[/tex] values here do not align with the determined parameters [tex]\(a = 2.23\)[/tex] and [tex]\(b = 2.54\)[/tex].

D. [tex]\( y = 2.84 \left(1.22^x\right) \)[/tex]

This also is an exponential equation, but like option C, it does not match our derived constants [tex]\(a\)[/tex] and [tex]\(b\)[/tex].

Thus, none of the provided options exactly match our derived exponential regression equation. However, let's compare the forms:

- Our derived equation: [tex]\( y = 2.23 \cdot (2.54^x) \)[/tex]
- Closest given option (C): [tex]\( y = 1.22 \cdot (2.84^x)\)[/tex]

Neither option perfectly matches the derived function, but we need to select the most plausible one.

The correct exponential regression equation based on the derived constants is:

[tex]\[ y = 2.23 \cdot (2.54^x) \][/tex]

Since this form is not given among the options, none of the answer choices provided (A, B, C, or D) correctly match the exponential regression equation derived from the data.

Ultimately, the detailed exponential regression analysis indicates that the fitting equation is:

[tex]\[ y = 2.23 \cdot (2.54^x) \][/tex]