Math Problem Statement

Misalkan portofolio L menawarkan tingkat return harapan sebesar 20% dengan standar deviasi 10%. Aset bebas risiko menawarkan return harapan sebesar 5%. Anggap Investor menginvestasikan 40% dananya pada aset bebas risiko dan 60% atau (100%-40%) pada portofolio L, maka:

Solution

The question is about an investor who divides their investment between a risk-free asset and a risky portfolio LL. The given information is:

  • Expected return of portfolio LL (E(RL)E(R_L)): 20%
  • Standard deviation of portfolio LL (σL\sigma_L): 10%
  • Risk-free rate (RfR_f): 5%
  • Investment allocation: 40% in the risk-free asset and 60% in portfolio LL.

Goal:

We are to calculate the expected return and standard deviation of this combined portfolio.


Step 1: Expected Return of the Portfolio

The formula for the expected return of a combined portfolio is:

E(Rp)=wfRf+wLE(RL)E(R_p) = w_f \cdot R_f + w_L \cdot E(R_L)

Where:

  • wf=40%=0.4w_f = 40\% = 0.4 (weight in risk-free asset)
  • wL=60%=0.6w_L = 60\% = 0.6 (weight in portfolio LL)
  • Rf=5%=0.05R_f = 5\% = 0.05
  • E(RL)=20%=0.2E(R_L) = 20\% = 0.2.

Substitute the values:

E(Rp)=(0.40.05)+(0.60.2)E(R_p) = (0.4 \cdot 0.05) + (0.6 \cdot 0.2) E(Rp)=0.02+0.12=0.14or14%E(R_p) = 0.02 + 0.12 = 0.14 \, \text{or} \, 14\%

Thus, the expected return of the portfolio is 14%.


Step 2: Standard Deviation of the Portfolio

The standard deviation of a portfolio with risk-free assets is proportional to the weight of the risky asset. The formula is:

σp=wLσL\sigma_p = w_L \cdot \sigma_L

Where:

  • wL=60%=0.6w_L = 60\% = 0.6
  • σL=10%=0.1\sigma_L = 10\% = 0.1.

Substitute the values:

σp=0.60.1\sigma_p = 0.6 \cdot 0.1 σp=0.06or6%\sigma_p = 0.06 \, \text{or} \, 6\%

Thus, the standard deviation of the portfolio is 6%.


Final Results:

  1. Expected return: 14%
  2. Standard deviation: 6%

Do you need further explanations or extensions on this solution?

Here are 5 related questions to deepen understanding:

  1. How would the expected return and risk change if the investor allocated 100% to portfolio LL?
  2. What happens to the portfolio risk if the weight in the risk-free asset increases to 70%?
  3. How do you calculate the Sharpe ratio of this combined portfolio?
  4. What is the impact of increasing the standard deviation of portfolio LL?
  5. How can the capital allocation line (CAL) help determine the optimal allocation?

Tip: Remember, combining risk-free assets with risky portfolios reduces overall risk while achieving better risk-adjusted returns.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Portfolio Theory
Expected Return
Risk Management

Formulas

Expected Return: E(Rp) = wf * Rf + wL * E(RL)
Portfolio Standard Deviation: σp = wL * σL

Theorems

Capital Market Line (CML)

Suitable Grade Level

Undergraduate Level (Finance, Economics)