Do the Math $7-3$

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 $($assume a $30-$day month and that the card balance is actually reduced on the day the payment is made$).$

a$.$ What was Kayla's average daily balance for April without new purchases? Round your answer to the nearest dollar. Use rounded answer for later calculations.

$

b$.$ What was her finance charge on the balance in part $($a$)$ if her APR is $19\mathrm{.}4$ percent? Round your answer to the nearest cent.

$

c$.$ What was her average daily balance for April with new purchases? Round your answer to the nearest dollar. Use rounded answer for later calculations. $

d$.$ What was her finance charge on the balance in part $($c$)$ if her APR is $19\mathrm{.}4$ percent? Round your answer to the nearest cent.

$