Please include each step and its explanation for better understanding. Thank you.

A company is thinking about opening a retail shopping centers (RB) of about 600,000 square feet to attract customers from three areas (Cl,C2, and C3). Currently there is a competing shopping center (RA) of about 1,000,000 square feet. The customer clusters have a buying potential of $10,$5, and $7 million respectively. Figure below represent the locations (in terms of travel time). Use Huff's method (use parameter a to be 2) to evaluate the sales potential for two potential locations for RB - namely (i) at (20,20) or (ii) (20, 50). Which one will you recommend