Need help looking for the standard deviation

Hyacinth Macaw invests 55% of her funds in stock I and the balance in stock J. The standard deviation of returns on I is 16%, and on J it is 23%. Note: Use decimals, not percents, in your calculations. a. Calculate the variance and standard deviation of portfolio returns, assuming the correlation between the returns is 1. b. Calculate the variance and standard deviation of portfolio returns, assuming the correlation is 0.6 . c. Calculate the variance and standard deviation of portfolio returns, assuming the correlation is 0 . Note: For all requirements, do not round intermediate calculations. Round your answers to 4 decimal places