Cumulative Exam Review

The table shows a company's profit based on the number of pounds of food produced.

\begin{tabular}{|c|c|}
\hline
Pounds of food produced & Profit (\[tex]$) \\
\hline
100 & $[/tex]-11,000[tex]$ \\
\hline
250 & 0 \\
\hline
500 & 10,300 \\
\hline
650 & 11,500 \\
\hline
800 & 9,075 \\
\hline
\end{tabular}

Using the quadratic regression model, which is the best estimate of the profit when 350 pounds of food are produced?

A. $[/tex]\[tex]$ 5,150$[/tex]

B. [tex]$\$[/tex] 5,300[tex]$

C. $[/tex]\[tex]$ 10,150$[/tex]

D. [tex]$\$[/tex] 11,000$



Answer :

To estimate the profit when 350 pounds of food are produced using a quadratic regression model, we follow these steps:

1. Collect the Data:
Given:
- Pounds of food produced: [tex]\[100, 250, 500, 650, 800\][/tex]
- Corresponding profits: [tex]\[-11,000, 0, 10,300, 11,500, 9,075\][/tex]

2. Fit a Quadratic Model:
A quadratic model can be expressed as:
[tex]\[ y = ax^2 + bx + c \][/tex]
where [tex]\( x \)[/tex] represents the pounds of food and [tex]\( y \)[/tex] represents the profit.

3. Determine Coefficients:
By fitting a quadratic model to the given data, we find the coefficients of the quadratic equation. The coefficients are:
[tex]\[ a = -0.0817, \quad b = 102.2355, \quad c = -20420.955 \][/tex]

4. Formulate the Quadratic Equation:
Substituting the coefficients into the quadratic equation gives:
[tex]\[ y = -0.0817x^2 + 102.2355x - 20420.955 \][/tex]

5. Estimate the Profit for 350 pounds:
To find the profit for 350 pounds of food produced, we substitute [tex]\( x = 350 \)[/tex] into the quadratic equation:
[tex]\[ y = -0.0817(350)^2 + 102.2355(350) - 20420.955 \][/tex]

6. Calculate the Estimated Profit:
Performing the calculations (and using the precise result obtained from the previous analysis):
[tex]\[ y \approx 5352.57 \][/tex]

Therefore, the estimated profit when 350 pounds of food are produced is approximately \$5,352.57. Among the given options, the closest estimate is:
[tex]\[ \boxed{5,300} \][/tex]