Hayes Electronics in Problem $1$ assumed with certainty that the ordering cost is $$450$ per order and the inventory carrying cost is $$170$ per unit per year. However, the inventory model parameters are frequently only estimates that are subject to some degree of uncertainty. Consider four cases of variation in the model parameters: $($a$)$ Both ordering cost and carrying cost are $10\%$ less than originally estimated, $($b$)$ both ordering cost and carrying cost are $10\%$ higher than originally estimated, $($c$)$ ordering cost is $10\%$ higher and carrying cost is $10\%$ lower than originally estimated, and $($d$)$ ordering cost is $10\%$ lower and carrying cost is $10\%$ higher than originally estimated. Determine the optimal order quantity and total inventory cost for each of the four cases. Prepare a table with values from all four cases and compare the sensitivity of the model solution to changes in parameter values.