Consider stock I whose return in period t can be described as:

R_i,t=1%+1.3R_M,t+e_i,t

Where R_i,t is stock is return in period t, R_M,t is the market return in period t, and e_i,t is stock is firm-specific return in period t, which is not correlated with anything.

R_M,t has a standard deviation of 15%,while e_i,t has a stand deviation of 20%.

What is the expected R² of a regression of stock is return on market return?