Parameters for curve calculation

The curve calculations all use the following parameters:

a, b, c	Curve coefficients
x	With Response per amount: Amount (ESTD), or amount ratio (ISTD) With Amount per response: Area, area%, height, or height% (ESTD) Area ratio or height ratio (ISTD)
y	With Response per amount: Area, area%, height, or height% (ESTD) Area ratio or height ratio (ISTD) With Amount per response: Amount (ESTD), or amount ratio (ISTD)
wt	Calibration level weighting factor