Question

The graph and accompanying table shown here display 12 observations of a pair of variables (x, y).
The variables x and y are positively correlated, with a correlation coefficient of r = 0.97.
What is the slope, b, of the least squares regression line, y = a + bx, for these data? Round your answer to the nearest hundredth.
x 3 6 8 9 9 13 15 18 20 21 23 23
y 9 17 15 15 18 24 29 36 43 39 46 55

Answer 1

Using R for the calculation:

> x<-c(3,6,8,9,9,13,15,18,20,21,23,23)
> y<-c(9,17,15,15,18,24,29,36,43,39,46,55)
> l<-lm(y~x)
> l

Call:
lm(formula = y ~ x)

Coefficients:
(Intercept) x
0.1281 2.0504

y=0.128+2.05x