Answer:
The new portfolio beta is 1.31 rounded off to two decimal places.
Explanation:
The portfolio beta is a function of the sum of the weighted average betas of the individual stock's that form up the portfolio. The portfolio beta is calculated using the following formula,
Portfolio beta = wA * Beta of A + wB * Beta of B + ... + wN * Beta of N
Where,
- w is the weightage of each stock in the portfolio
The beta of the portfolio when one stock with a beta of 1 is sold is,
The sum of individual stock betas for 19 stocks is = 20 * 1.31 - 1 * 1 = 25.2
The new portfolio beta when one stock with a beta of 0.97 is added is,
Portfolio beta = (25.2 + 0.97) / 20
Portfolio beta = 1.3085 rounded off to 1.31