standard deviation throws me off and i dont know what to do with it

What are the expected return and standard deviation for a portfolio that has $2,000 invested in a risk-free asset with 5.25% rate of return, and $8,000 invested in a risky asset with a 21% rate of return and a 35% standard deviation? O O O O Expected return = 28.00%; standard deviation = 17.85% Expected return = 7.00%; standard deviation = 8.40% Expected return = 17.85%; standard deviation = 28.00% Expected return = 8.40%; standard deviation = 7.00%