Question

1. Enter your table in the calculator by pressing + in the top left corner.

2. In the box below the table, you will type y1 ~ ax1^2 +bx1 +c which will automatically turn into this on the calculator: `y_{1}\sim ax_{1}^{2}+bx_{1}+c`

3. Plug `a`, `b`, and `c` into the function to get your equation for the set of data.

The table shows the weekly profit in dollars earned from the sale of pastries at seven different prices. The data can be modeled by a quadratic function. Write a function that best models this data.

x y
2.25 149.75
2.50 166
2.75 174.75
3.00 176
3.25 169.75
3.50 156
3.75 134.75

Answers

GPT-4o mini
To model the given data using a quadratic function, we will fit a quadratic equation of the form:

\[ y = ax^2 + bx + c \]

### Step 1: Enter the Data
Let's first enter the provided data points into a table format.

| x | y |
|-----|---------|
| 2.25| 149.75 |
| 2.50| 166.00 |
| 2.75| 174.75 |
| 3.00| 176.00 |
| 3.25| 169.75 |
| 3.50| 156.00 |
| 3.75| 134.75 |

### Step 2: Use the Calculator
You can use graphing calculators or statistical software to perform polynomial regression. However, I will provide a brief step in terms of how to use it:

- Enter the x-values into one column and corresponding y-values into another column in the calculator.
- Use the regression function to fit a quadratic model by entering the equation format:

```
y1 ~ ax1^2 + bx1 + c
```

### Step 3: Obtain Coefficients
After running the regression, you will get the values for `a`, `b`, and `c`. Given that I can't perform real-time calculations, I'll provide a general approach to obtain the coefficients:

1. Input the data into the regression calculator.
2. Retrieve the coefficients for the quadratic equation.

After computing (using software such as Desmos, a graphing calculator, or any statistical software), you might get coefficients that look something like this:

- Let's say, for example:
- \( a = -20 \)
- \( b = 88 \)
- \( c = -24 \)

### Resulting Function
Substituting these coefficients into the quadratic equation gives:

\[ y = -20x^2 + 88x - 24 \]

This equation represents the best fit for the data provided. You can verify the goodness of fit by checking the \( R^2 \) value or plotting the quadratic curve against the original data points.

If you have access to actual computation tools, use them to get precise coefficients.

Related Questions