Beta of the portfolio is?

pls tell me beta of index fund,, then only possible to calculate beta of portfolio

in which exam???

Beta of index fund is 1. Beta of a treasury bill is 0. Beta of the portfolio is the weighted average of the components. That is 0.07 x 1.72 + 0.28 x 0.89 + 0.25 x 0 + 0.43 x 1 =  0.7996.

Treasury bill doesn't move with the equity market, therefore it's beta is 0. As rightly said index fund is the market itself therefore its beta is 1.

Hope this clarifies.  

CMA Final June 2013 Paper 11

@ rahul - T bills are not zero beta stocks. they are debt instruments, not equity. Hence it's beta is zero. Also they are not zero beta because they are issued by govt. Even corporate debt also has zero beta. 

Beta is a measure of non diverisfiable risk, also known as the residual risk , which cannot be diversifed even if we collect two negatively correlated securities in our portfolio. It can also be described as the senstivity of a security with respect to market

Treasury Bills: These are risk free securities which do not have any sensitivity to market changes. Hence the beta is 0

Also, the market related security will be perfectly in tandem with the market, or precisely the sensitivity shall be 1. Therefore , beta shall be 1