Katie's portfolio of shares comprised of investments of $9,200 in the telecommunications industry and $13,300 in the information technology industry. The market price of his telecommunications shares decreased by 55% and that of information technology increased by 50%. a. Calculate the total market value of his investments after the changes. Round to the nearest cent b. By what percent did the total market value of his investments change? % Express the answer with a positive sign for an increase or negative sign for a decrease, rounded to two decimal places