Given the data points of the function [tex]\( f(x) \)[/tex], we want to find the quadratic function in standard form:
[tex]\[ f(x) = ax^2 + bx + c \][/tex]
We are given that:
[tex]\[
\begin{array}{|c|c|c|c|c|c|c|}
\hline
x & 0 & 2 & 4 & 6 & 8 & 10 \\
\hline
f(x) & 10 & 15 & 18 & 19 & 18 & 15 \\
\hline
\end{array}
\][/tex]
To determine the coefficients [tex]\( a \)[/tex], [tex]\( b \)[/tex], and [tex]\( c \)[/tex], we can use quadratic regression analysis. From this analysis, we find:
[tex]\[ a = -0.25000000000000033 \][/tex]
[tex]\[ b = 3.0000000000000036 \][/tex]
[tex]\[ c = 9.999999999999996 \][/tex]
Therefore, the quadratic function that models the number of guests per month is:
[tex]\[ f(x) = -0.25x^2 + 3x + 10 \][/tex]