A manufacturer incurs the following costs in producing x water ski vests in one day, for 0

A manufacturer incurs the following costs in producing x water ski vests in one day, for fixed costs, $320; unit production cost, $20 per vest; equipment maintenance and repairs, 0.05x2 dollars.So, the cost of manufacturing x vests in one given day is given by where a. What is the average cost AC(x) per vest if x vests are produced in one day? b. Find the critical values of AC(x) and the local extrema. Based on this information, what production level would you recommend for the company and why?