Marcus's portfolio of shares comprised of investments of $7,600 in the telecommunications industry and $11,600 in the information technology industry. The market price of her telecommunications shares decreased by 40% and that of information technology increased by 45%.

a. Calculate the total market value of her investments after the changes.

Round to the nearest cent

b. By what percent did the total market value of her investments change?

Express the answer with a positive sign for an increase or negative sign for a decrease, rounded to two decimal places