Finding the Bootstrap Prediction Interval Suppose we're visiting Point Reyes and stumble upon some Snowy Plover eggs; we'd like to know how heavy they'll be once they hatch. In other words, we want to use our regression line to make predictions about a bird's weight based on the weight of the corresponding egg. However, just as we're uncertain about the slope of the true regression line, we're also uncertain about the predictions made based on the true regression line