a. Calculate an envelope portfolio assuming the risk-free rate is 4%.b. Calculate an envelope portfolio assuming the risk-free rate is 10%.c. Using EXCELs Data Table Feature, create a one-way data table that determines the differentmeans and standard deviations for combinations of Envelope Portfolio 1 and EnvelopePortfolio 2 by varying the proportion of Portfolio 1 from -4 to +4 in increments of 0.40.d. Graph the combinations of the portfolios from the one-way data table and add theindividual asset m