How did you calculate the slop of the trend line?

Answer 1

To calculate the slope of the trend line, I used the formula ( m = \frac{(N \sum xy) - (\sum x)(\sum y)}{(N \sum x^2) - (\sum x)^2} ), where ( N ) is the number of data points, ( \sum xy ) is the sum of the product of each pair of x and y values, ( \sum x ) is the sum of the x values, ( \sum y ) is the sum of the y values, and ( \sum x^2 ) is the sum of the squares of the x values. This formula derives from the least squares method, which minimizes the distance between the actual data points and the trend line. After computing the necessary sums, I substituted them into the formula to find the slope.