Final answer:
To find the portfolio's new beta, calculate the weighted average beta of the remaining stocks and add the new stock's beta. The portfolio's new beta will be 2.05.
Step-by-step explanation:
To find the portfolio's new beta, we need to calculate the weighted average beta of the remaining stocks in the portfolio, and then add the new stock's beta.
First, calculate the total value of the portfolio before selling the stock:
Total Value = $7,500 * 20 = $150,000
Next, calculate the portion of the portfolio's beta contributed by each stock:
Portfolio Beta = Average Beta * Total Value / Stock Value
For the stock being sold (with a beta of 1.0), the contributed beta is:
Contribution of Stock Being Sold = 1.0 * $7,500 / $7,500 = 1.0
Now, calculate the new stock's contribution to the portfolio's beta:
Contribution of New Stock = 1.4 * $7,500 / $7,500 = 1.4
Finally, calculate the weighted average beta of the remaining stocks:
Remaining Beta = (Portfolio Beta - Contribution of Stock Being Sold) / (Total Value - Stock Value) * (Total Value - Stock Value) / Total Value
Substituting the known values:
Remaining Beta = (0.75 * $150,000 - 1.0) / ($150,000 - $7,500) * ($150,000 - $7,500) / $150,000
Simplifying the equation:
Remaining Beta = 0.65
Finally, the portfolio's new beta is:
New Beta = Remaining Beta + Contribution of New Stock = 0.65 + 1.4 = 2.05