**mean return of the stocks in the group is 10%**per year and the

**variance of the returns of the stocks in the group is 4% per year.**

a)Calculate the expected return and variance of the 14 stock portfolios.

... do i have to break down the mean return and variance for each group?

b)Calculate a 90% confidence interval for the portfolio return.

:? any help with equations, i really appreciate your time.

thank you.