a. Compute the rate of return on an equally weighted index of the three defense stocks for the year ending December 31,2019 . (A negative value should be indicated by a minus sign. Do not round intermediate calculations. Enter your answer as a percent rounded to 2 decimal places.) b. If the index value is set to 100 on January 1, 2019, what will the index value be on January 1, 2020? (Do not round intermediate calculations. Round your answer to 2 decimal places.) c. What is the rate of return on the index for 2020? (Do not round intermediate calculations. Enter your answer as a percent rounded to 2 decimal places.)