3. Average Daily Balance and Finance Charges. Kayla Sampson, an antiques dealer from Mankato, Minnesota, received her monthly billing statement for April for her MasterCard account. The statement indicated that she had a beginning balance of $600, on day 5 she charged $150, on day 12 she charged $300, and on day 15 she made a $200 payment. Out of curiosity, Kayla wanted to confirm that the finance charge for the billing cycle was correct. (a) What was Kayla's average daily balance for April without new purchases? (b) What was her finance charge on the balance in part (a) if her APR is 19.2 percent? (c) What was her average daily balance for April with new purchases? (d) What was her finance charge on the balance in part (c) if her APR is 19.2 percent