Need assistance with these questions. I keep getting the wrong answers.

1.) Grunewald Industries sells on terms of 3/10, net 40. Gross sales last year were $4,161,000 and accounts receivable averaged $370,500. Half of Grunewald's customers paid on the 10th day and took discounts. What are the nominal and effective costs of trade credit to Grunewald's non-discount customers? (Hint: Calculate daily sales based on a 365-day year, calculate the average receivables for discount customers, and then find the DSO for the non-discount customers.) Do not round intermediate calculations. Round your answers to two decimal places. Effective cost of trade credit = 2.) Negus Enterprises has an inventory conversion period of 55 days, an average collection period of 42 days, and a payables deferral period of 20 days. Assume that cost of goods sold is 80% of sales. Assume a 365-day year. Do not round intermediate calculations. If annual sales are $4,635,500 and all sales are on credit, what is the firm's investment in accounts receivable? Round your answer to the nearest dollar