Calculates the main statistics of a linear regression: the slope
and intercept of the line, the coefficient of determination,
also known as r-square, the standard error of the slope, and the
p-value for the regression. This function takes two equal-length
sequences of raw data. Note that the dependent variable, as
always, comes first in the argument list. You should first look
at your data with a scatter plot to see if a linear model is
plausible. See the manual for a fuller explanation of linear
regression