Suppose that the weekly demand forecast of $90$ bags is incorrect and actual demand averages only $60$ bags per week. How much higher will total costs be$,$ owing to the distorted EOQ caused by this forecast error?

Suppose that actual demand is $60$ bags but that ordering costs are cut to only $$6$ by using the Internet to automate order placing. However, the buyer does not tell anyone, and the EOQ is not adjusted to reflect this reduction in S$.$ How much higher will total costs be$,$ compared to what they could be if the EOQ were adjusted?