Can somebody help me to calculate the Beta of this portfolio?

Question

Microsoft /// Apple /// NASDAQ

Variance 0.000172 /// 0.000657 /// 0.000083

St deviation 0.013119 /// 0.025638 /// 0.009093


correlation /// microsoft /// apple /// NASDAQ
coefficient

with microsoft /// 1.000000 /// 0.169784 /// 0.457820

with apple /// 0.169784 /// 1.000000 /// 0.446451





THANKS A LOT!

Answer 1

You need three things to know beta of a portfolio:
1) Weighting
2) Co-variance to each other
3) Index against which you are benchmarking your beta

You have given the second and the third is not really required to get the answer, but you definitely need the third. Is this an equal-dollar weighted portfolio or equal market weighted?