It appears that the simple_linear_regression routine in stats works for n < 345.
The following works, but n > 344 results in this message: gamma: overflow in GAMMAFLOAT.
load(stats)$
n: 344$
rL : makelist(2*random(3.0), i, 0, n) $
xL : makelist(i, i, 0, n)$
yL :-20+xL+rL$
data: map("[", xL,yL)$
simple_linear_regression(data);