$4\mathrm{.}2$ If unit $1$ requires $200$ hours to produce and the labor records for an Air Force project contract of $50$ units indicates an average labor content of $63\mathrm{.}1$ hours per unit, what was the learning rate? What total additional number of labor hours would be required for a follow$-$on Air Force contract of $50$ units? What would be the average labor content of this second contract? Of both contracts combined? If labor costs the vendor $$10/$hour on this second contract and the price to the Air Force is fixed at $$550$ each, what can you say about the profitability of the first and second contracts, and hence the bidding process in general?