Suppose we t a regression line to predict the shelf life of an apple based on its weight. For a particular apple, we predict the shelf life to be 4.6 days. The apples residual is - 0.6 days. Did we over or under estimate the shelf-life of the apple? Explain your reasoning.

Step-by-step explanation:

Given that we fit a regression line to predict the shelf life of an apple based on its weight.

When we fit regression line for a data set, we use least squares concept.

The line which is very nearly fitting the scatter plot is selected in such a ways that the sum of squares of deviations from this line are minimum.

Normally actual value for a particular x and as per line would be different

Residual = Actual y - predicted y as per regression line

Here prediction is 4.6 and residual is - 0.6

A residual is negative if actual observed value is less than the predicted value

Hence here we predicted 4 as 4.6 days hence we overestimated the shelf life by 0.6 days