Answer
Twain used the concept of the least squares regression to predict the length of the Mississippi with time and other factors. According to Twain, a million years ago, the Mississippi was more than one million and three hundred thousand miles long, and after 742 years, it would be a mile and three quarters long.
Work Step by Step
The concept of regression is used by Twain to predict the length of the Mississippi with time and other factors. The length of the Mississippi is considered as the response variable, whereas the time and the other factors are considered as the explanatory variable. Twain used the length of the Mississippi at different time points, and also collected the data on the cause of the reduction of the length. To obtain the result that the Mississippi is more than one million and three hundred thousand miles long, and after 742 years, it would be a mile and three quarters long, the least squares regression method is used.
