Fitting a straight-line trend by least squares, with x = 0 at 2022 and x in years, what is the slope of the…

Explanation

1. 01

   $x = -2, -1, 0, 1, 2$: $\sum xy = -84 - 45 + 0 + 54 + 120 = 45$ and $\sum x^{2} = 10$.

2. 02

   $b = \frac{\sum xy}{\sum x^{2}} = \frac{45}{10} = 4.5$.