👉 In mathematics, a "fitted" object is one that can be fitted to data. This means that it is an object that best fits the data, meaning that it minimizes some objective function (such as minimizing the mean squared error or maximizing the likelihood) for some given data points.
For example, consider a model where we want to predict y based on x, which has a linear relationship with x:
fitted(y, x) = b0 + b1
x
where b0