3. Determine the effective rate of interest associated with a nominal rate of 6.79%, compounded quarterly. Give your final answer as a percentage, rounded to 2 decimal places. 4. The marginal prot in dollars on a type of cheese sold at a cheese store is given by the pix] =x[50x2 +30x], . function where X is the amount of cheese sold, 1n hundreds of pounds. If the prot from selling 200 pounds of cheese is $240, determine the profit function PiX). 1. An investment in a 4.3% interest bearing account, compounded monthly, earns $30000 after 7 years. Determine the original balance in the account, rounded to the nearest cent. 2. Determine how long it will take (to the nearest tenth of a year) for a $6000 balance to triple in an account with 7.4% interest, compounded continuously. Show your work algebraically