c. How useful do you think this regression model is for predicting the monthly rent?
13.79 An accountant for a large department store would like to develop a model to predict the amount of time if takes to process invoices. Data are collected from the past 32 working days, and the number of invoices processed and completion time (in hours) are stored in Invoice. (Hint: First, determine which are independent and dependent variables.)  
http://www.mediafire.com/?gs7w5ft5owuz2of  
a. Assuming a linear relationship, use the leastsquares method to compute the regression coefficients b0 and b1.  
b.Interpret the meaning of the Y intercept, B0, and the slope, b1, in this problem.  
c. Use the prediction line developed in (a) to predict the amount of time it would take to process 150 invoices.  
d. Determine the coefficient of determination, r^2, and interpret its meaning.
