Program a linear regression model from first principles (i.e. you are not allowed to make use of any libraries, either internal or external) that solves for the best least squares method. Your user must be allowed to enter any number of observations for both the dependent and independent variable. Once the number of observations is captured, you must solve for the best linear regression fit as well as the R2 value. Your results must also display the difference between the predicted and dependent observation for each point. (C Programming)