Calculator
Regression Models
A mathematical model is an
equation that best describes a particular set of paired data.
The mathematical models shown here are referred to as
regression models and are used to
predict one variable based upon another variable.
The linear based regression models on the graphing calculator:
• Linear (LinReg) 
y = ax + b 
The graph of x versus y is linear.

Fits Linear by
Transformations: 
• Logarithmic (LnReg) 
y = a
+ b ln(x) 
The graph of ln(x)
versus y is linear. Calculates
a and b using linear least squares on lists of ln(x)
and y instead of x and y. 
• Exponential (ExpReg) 
y = a (b^{ x}) 
The graph of x versus
ln(y) is linear. Calculates A and B using linear least squares on
lists of x and ln(y) instead of x and
y, and then
a = e^{A} and b = e^{B}
. 
• Power (PwrReg) 
y = a ( x^{ b}) 
The graph of ln(x)
versus ln(y) is linear. Calculates A and b using liner least squares
on list of ln(x) and ln(y) instead of x
and y, and then
a = e^{A}. 
Other models available on the
graphing calculator:
• Quadratic (QuadReg)


For three points, fits a polynomial to the
data. For more than three points, fits a polynomial
regression. 
• Cubic (CubicReg)


For four points, fits a polynomial to the data.
For more than four points, fits a polynomial regression. 
• Quartic (QuartReg)


For five points, fits a polynomial to the data.
For more than five points, fits a polynomial regression. 
• Logistic (Logistic)


Fits equation to data using iterative leastsquares fit. 
• Sinusoidal (SinReg)


Fits sine wave to data using iterative leastsquares
fit.

