A simple linear regression approach.
I am giving a set of inputs x which is the diameter of pizza in inches and y is set of outputs (price in dollars)
x=[[6],[8],[10],[14],[18],[21]]
y=[[7],[9],[13],[17.5],[18],[24]]
A model is fitted using LinearRegression() to predict the price for a pizza of a given diameter, here diameter is given as 21 inches