The stock of a technology company has an expected return of 15% and a standard deviation of 20% The stock of a pharmaceutical company has an expected return of 13% and a standard deviation of 18%. A portfolio consisting of 50% invested in each stock will have an expected return of 14 % and a standard deviation.

I got the correct answer it looks like, but I would like to verify if I used the right formula. This was the calculation I used, but not sure if that's correct?

(.50x15)+(.50x13) = 14

Answer: less than the average of 20% and 18%