HP 33s ƒ(xi − x)2 ⎟ n, |s, G–3, ƒ(yi − y )2 ⎟ n, Operation Index G–3

Name	Keys and Description	Page	¼
Σ+	Accumulates (y, x) into	11–2
	statistics registers.
Σ–	{Removes (y, x) from	11–2
	statistics registers.
Σx	{;º}	11–10	1
	Returns the sum of x–values.
Σx2	{;º}	11–10	1
	Returns the sum of squares of
	x–values.
Σxy	{;º¸}	11–10	1
	Returns the sum of products of
	x–and y–values.
Σy	{;¸}	11–10	1
	Returns the sum of y–values.
Σy2	{;¸}	11–10	1
	Returns the sum of squares of
	y–values.
σx	{σº}	11–6	1
	Returns population standard
	deviation of x–values:
	ƒ(xi − x)2 ⎟ n
σy	{σ¸}	11–6	1
	Returns population standard
	deviation of y–values:
	ƒ(yi − y )2 ⎟ n
θ, r€y,x	s	4–9
	Polar to rectangular coordinates.
	Converts (r, θ) to (x, y).

Operation Index G–3