If the indirect costs for each duration are $$1200$ for $16$ weeks, $$1130$ for $15$ weeks, $$1000$ for $14$ weeks, $ $900$ for $13$ weeks, $$860$ for $12$ weeks, $ $820$ for $11$ weeks and $ $790$ for $10$ weeks, compute total costs for each duration. Plot these costs on a graph. What is the optimum cost time schedule?