Correct Answer: B) 15.5%
This is a weighted average expected return problem. We need to calculate the bank's new expected return after adding the branch.
Step 1: Identify the information given.
Existing bank expected return = 15%
New branch expected return = 20%
Existing bank weight = 90%
New branch weight = 10%
The new branch represents 10% of the combined bank's revenues, so the existing bank represents the remaining 90%.
Step 2: Use the weighted average return formula.
Expected Return = (Weight of Existing Bank × Existing Return) + (Weight of New Branch × New Branch Return)
Step 3: Substitute the numbers.
Expected Return = (0.90 × 15%) + (0.10 × 20%)
Expected Return = 13.5% + 2%
Expected Return = 15.5%
Final Answer: B) 15.5%
Why don't we use the standard deviations or correlation?
The problem provides:
- Existing bank standard deviation = 7%
- New branch standard deviation = 10%
- Correlation = -0.3
These numbers are used to calculate the risk (standard deviation) of the combined bank, not its expected return.
The negative correlation suggests that the returns of the existing bank and new branch tend to move in opposite directions, which can provide diversification benefits.
However, correlation does not affect the weighted average expected return.
Easy Way to Remember:
Expected Return = Weighted Average of Returns
Portfolio Risk = Depends on Standard Deviations AND Correlation
For example, imagine you have $90 invested in something earning 15% and $10 invested in something earning 20%.
Your total expected return is not 35%. It is the weighted average of the two returns, which equals 15.5%.
Answer: B) 15.5%