Williams Incorporated produces fluorescent light bulbs for commercial use. The accounting manager is attempting to estimate the total cost for the next quarter using the high-low method. He has compiled data and found the high and low costs are $46,100 and $35,500, respectively, and the associated cost drivers are 8,100 and 2,800 packs, respectively. What is the value for b (the variable cost per unit)? What is the value for a (the fixed quantity)?