HP -22S Owner's Manual page 172

Statistical Functions
};X·
x=-'
n
SX
= , /
};(Xj -
X)2
V
n -
1
- _ };Yi
y - -
n
, I
};(!lj -
jj)
Sy=
V
n - l
m=
};(xi -
x)
Wi -
y)
};(xi -
X)2
b=y-mx
172 C: Equations Used by HP-22S Functions