Field Guide/Statistics/Other regression models
Core3 min

Compare quadratic and exponential regression

A scatter plot is curved and theory suggests quadratic or multiplicative behavior.

01

Press these keys

STATCALC5:QuadReg / 0:ExpReg

Step 1 of 3. Press STAT.

02

Walkthrough

  1. 1
    Inspect shape first

    Use a scatter plot; do not choose a model only because its r² is high.

  2. 2
    Run candidate model

    STAT → CALC → QuadReg or ExpReg with L1 and L2.

  3. 3
    Check residuals

    After regression, residuals are stored in RESID; a residual plot should not show a systematic pattern.

03

Worked example

Fit y=3·2ˣ data at x=0,1,2,3.

Answerŷ=3(2)ˣ.