Simple Linear Regression for a Numerical Explanatory Variable

Recall the concepts of algebra that the equation of a line is $𝑦 = 𝑎 + 𝑏 ⋅ 𝑥$. (Note that the ⋅ symbol is equivalent to the * “multiply by” mathematical symbol. We’ll use the ⋅ symbol in the rest of this course as it’s more succinct.) It’s defined by two coefficients $𝑎$ and $𝑏$. The intercept coefficient $𝑎$ is the value of $𝑦$ when $x$ = 0. The slope coefficient $𝑏$ ...