14.7 vectorization / broadcasting

my_vec <- c(1, 2, 3, 4, 5, 6)

my_vec * 2
## [1]  2  4  6  8 10 12

my_vec * c(2, 100)
## [1]   2 200   6 400  10 600

\(\sum_{i = 0}^n\dfrac{(x_i - \bar{x})^2}{n -1}\)

n_1 <- length(my_vec) - 1
x_bar <- mean(my_vec)

sum(((my_vec - x_bar)^2) / n_1)
## [1] 3.5