Use the table to answer the question.

x y
0 12
1 14
2 16
3 18
4 20
Devin creates a table showing five points. He uses a spreadsheet calculator to calculate the slope and y-intercept of the least squares regression line based on the points in the table. What is the slope of this line?(1 point)
The slope of the least squares regression line is

1 answer

To calculate the slope of the least squares regression line based on the given points, we can use the formula for the slope \( m \) of the regression line:

\[ m = \frac{n(\sum xy) - (\sum x)(\sum y)}{n(\sum x^2) - (\sum x)^2} \]

where:

  • \( n \) is the number of points,
  • \( \sum xy \) is the sum of the product of each x and y,
  • \( \sum x \) is the sum of all x values,
  • \( \sum y \) is the sum of all y values, and
  • \( \sum x^2 \) is the sum of the squares of each x value.

First, calculate the necessary sums from the table provided:

| x | y | xy | x² | |---|----|----|----| | 0 | 12 | 0 | 0 | | 1 | 14 | 14 | 1 | | 2 | 16 | 32 | 4 | | 3 | 18 | 54 | 9 | | 4 | 20 | 80 | 16 |

Now we compute the sums:

  • \( \sum x = 0 + 1 + 2 + 3 + 4 = 10 \)
  • \( \sum y = 12 + 14 + 16 + 18 + 20 = 80 \)
  • \( \sum xy = 0 + 14 + 32 + 54 + 80 = 180 \)
  • \( \sum x^2 = 0 + 1 + 4 + 9 + 16 = 30 \)

Now plug these values into the slope formula:

  • \( n = 5 \)

\[ m = \frac{5(180) - (10)(80)}{5(30) - (10)^2} \] \[ m = \frac{900 - 800}{150 - 100} \] \[ m = \frac{100}{50} = 2 \]

Thus, the slope of the least squares regression line is \( \boxed{2} \).