Consider the following table: Required: a. Calculate the values of mean return and variance for the stock fund. (Do not round intermediate calculations. Round "Mean refurn" value to 1 decimal place and "Variance" to 4 decimal places.) b. Calculate the value of the covariance between the stock and bond funds. (Negative value should be indicated by a minus sign. Do not round intermediate calculations. Round your answer to 4 decimal places.)