Sales/365 * 45 days = WC requirementÂ
This is the AR assuming that none of the customers pays till required to at the end of the 45 Days.Â
630000/365 *45 = 77671 ( Per the question the sales are uniform across the period so this is valid)
We have already included a WC of $30K at the time of the initial investment. so the change in the WC that is needed to meet the new WC requirement based on the credit policy is
WC requirement - WC initial investment = 77671 - 30,000 = 47671