To determine the least squares regression line, we need to calculate the slope (m) and y-intercept (b) of the line represented by the formula \(y = mx + b\).
Given the data points: \[ \begin{align*} x: & \quad -5, -4, -3, -2, -1 \ y: & \quad 3, 4, 7, 7.5, 2.5 \ \end{align*} \]
Using a spreadsheet calculator or statistical software, we can input this data and compute the regression line.
To calculate the regression using the least squares method, the following formulas are typically used:
-
The slope \(m\): \[ m = \frac{N(\sum xy) - (\sum x)(\sum y)}{N(\sum x^2) - (\sum x)^2} \]
-
The y-intercept \(b\): \[ b = \frac{\sum y - m(\sum x)}{N} \]
Where:
- \(N\) is the number of points
- \(\sum\) denotes the summation over all points
After performing these calculations (or using a spreadsheet), you should find that the least squares regression line is:
y = 5.55x + 0.25.
So the correct choice is: y = 5.55x + 0.25.