what is the variance and standard deviation of each stock?

Ri=i+i,1I1+i,2I2+i Where, E(i)=0;Var(i)=e,i2 Assuming Ij are uncorrelated and T1=8%,I2=4%,11=0.02 and 12=0.025, calculate: Ri=i+i,1I1+i,2I2+i Where, E(i)=0;Var(i)=e,i2 Assuming Ij are uncorrelated and T1=8%,I2=4%,11=0.02 and 12=0.025, calculate