Asset X:
Returns: 8%, 9%, 11%, 12%
Probabilities: 0.10, 0.20, 0.30, 0.40
Expected Return:
E ( X ) = ( 0.08 ) ( 0.10 ) + ( 0.09 ) ( 0.20 ) + ( 0.11 ) ( 0.30 ) + ( 0.12 ) ( 0.40 ) E(X) = (0.08)(0.10) + (0.09)(0.20) + (0.11)(0.30) + (0.12)(0.40) E ( X ) = ( 0.08 ) ( 0.10 ) + ( 0.09 ) ( 0.20 ) + ( 0.11 ) ( 0.30 ) + ( 0.12 ) ( 0.40 ) E ( X ) = 0.008 + 0.018 + 0.033 + 0.048 = 0.107 E(X) = 0.008 + 0.018 + 0.033 + 0.048 = 0.107 E ( X ) = 0.008 + 0.018 + 0.033 + 0.048 = 0.107 E ( X ) = 10.7 % E(X) = 10.7\% E ( X ) = 10.7%
Variance:
V a r ( X ) = ∑ [ x i − E ( X ) ] 2 ∗ P ( x i ) Var(X) = \sum [x_i - E(X)]^2 * P(x_i) Va r ( X ) = ∑ [ x i − E ( X ) ] 2 ∗ P ( x i ) V a r ( X ) = ( 0.08 − 0.107 ) 2 ( 0.10 ) + ( 0.09 − 0.107 ) 2 ( 0.20 ) + ( 0.11 − 0.107 ) 2 ( 0.30 ) + ( 0.12 − 0.107 ) 2 ( 0.40 ) Var(X) = (0.08 - 0.107)^2(0.10) + (0.09 - 0.107)^2(0.20) + (0.11 - 0.107)^2(0.30) + (0.12 - 0.107)^2(0.40) Va r ( X ) = ( 0.08 − 0.107 ) 2 ( 0.10 ) + ( 0.09 − 0.107 ) 2 ( 0.20 ) + ( 0.11 − 0.107 ) 2 ( 0.30 ) + ( 0.12 − 0.107 ) 2 ( 0.40 ) V a r ( X ) = ( − 0.027 ) 2 ( 0.10 ) + ( − 0.017 ) 2 ( 0.20 ) + ( 0.003 ) 2 ( 0.30 ) + ( 0.013 ) 2 ( 0.40 ) Var(X) = (-0.027)^2(0.10) + (-0.017)^2(0.20) + (0.003)^2(0.30) + (0.013)^2(0.40) Va r ( X ) = ( − 0.027 ) 2 ( 0.10 ) + ( − 0.017 ) 2 ( 0.20 ) + ( 0.003 ) 2 ( 0.30 ) + ( 0.013 ) 2 ( 0.40 ) V a r ( X ) = ( 0.000729 ) ( 0.10 ) + ( 0.000289 ) ( 0.20 ) + ( 0.000009 ) ( 0.30 ) + ( 0.000169 ) ( 0.40 ) Var(X) = (0.000729)(0.10) + (0.000289)(0.20) + (0.000009)(0.30) + (0.000169)(0.40) Va r ( X ) = ( 0.000729 ) ( 0.10 ) + ( 0.000289 ) ( 0.20 ) + ( 0.000009 ) ( 0.30 ) + ( 0.000169 ) ( 0.40 ) V a r ( X ) = 0.0000729 + 0.0000578 + 0.0000027 + 0.0000676 = 0.000201 Var(X) = 0.0000729 + 0.0000578 + 0.0000027 + 0.0000676 = 0.000201 Va r ( X ) = 0.0000729 + 0.0000578 + 0.0000027 + 0.0000676 = 0.000201
Standard Deviation:
S D ( X ) = V a r ( X ) = 0.000201 ≈ 0.014177 SD(X) = \sqrt{Var(X)} = \sqrt{0.000201} \approx 0.014177 S D ( X ) = Va r ( X ) = 0.000201 ≈ 0.014177 S D ( X ) ≈ 1.42 % SD(X) \approx 1.42\% S D ( X ) ≈ 1.42%
Coefficient of Variation:
C V ( X ) = S D ( X ) E ( X ) = 0.014177 0.107 ≈ 0.1325 CV(X) = \frac{SD(X)}{E(X)} = \frac{0.014177}{0.107} \approx 0.1325 C V ( X ) = E ( X ) S D ( X ) = 0.107 0.014177 ≈ 0.1325 or 13.25%
Asset Y:
Returns: 10%, 11%, 12%
Probabilities: 0.25, 0.35, 0.40
Expected Return:
E ( Y ) = ( 0.10 ) ( 0.25 ) + ( 0.11 ) ( 0.35 ) + ( 0.12 ) ( 0.40 ) E(Y) = (0.10)(0.25) + (0.11)(0.35) + (0.12)(0.40) E ( Y ) = ( 0.10 ) ( 0.25 ) + ( 0.11 ) ( 0.35 ) + ( 0.12 ) ( 0.40 ) E ( Y ) = 0.025 + 0.0385 + 0.048 = 0.1115 E(Y) = 0.025 + 0.0385 + 0.048 = 0.1115 E ( Y ) = 0.025 + 0.0385 + 0.048 = 0.1115 E ( Y ) = 11.15 % E(Y) = 11.15\% E ( Y ) = 11.15%
Variance:
V a r ( Y ) = ∑ [ y i − E ( Y ) ] 2 ∗ P ( y i ) Var(Y) = \sum [y_i - E(Y)]^2 * P(y_i) Va r ( Y ) = ∑ [ y i − E ( Y ) ] 2 ∗ P ( y i ) V a r ( Y ) = ( 0.10 − 0.1115 ) 2 ( 0.25 ) + ( 0.11 − 0.1115 ) 2 ( 0.35 ) + ( 0.12 − 0.1115 ) 2 ( 0.40 ) Var(Y) = (0.10 - 0.1115)^2(0.25) + (0.11 - 0.1115)^2(0.35) + (0.12 - 0.1115)^2(0.40) Va r ( Y ) = ( 0.10 − 0.1115 ) 2 ( 0.25 ) + ( 0.11 − 0.1115 ) 2 ( 0.35 ) + ( 0.12 − 0.1115 ) 2 ( 0.40 ) V a r ( Y ) = ( − 0.0115 ) 2 ( 0.25 ) + ( − 0.0015 ) 2 ( 0.35 ) + ( 0.0085 ) 2 ( 0.40 ) Var(Y) = (-0.0115)^2(0.25) + (-0.0015)^2(0.35) + (0.0085)^2(0.40) Va r ( Y ) = ( − 0.0115 ) 2 ( 0.25 ) + ( − 0.0015 ) 2 ( 0.35 ) + ( 0.0085 ) 2 ( 0.40 ) V a r ( Y ) = ( 0.00013225 ) ( 0.25 ) + ( 0.00000225 ) ( 0.35 ) + ( 0.00007225 ) ( 0.40 ) Var(Y) = (0.00013225)(0.25) + (0.00000225)(0.35) + (0.00007225)(0.40) Va r ( Y ) = ( 0.00013225 ) ( 0.25 ) + ( 0.00000225 ) ( 0.35 ) + ( 0.00007225 ) ( 0.40 ) V a r ( Y ) = 0.0000330625 + 0.0000007875 + 0.0000289 = 0.00006275 Var(Y) = 0.0000330625 + 0.0000007875 + 0.0000289 = 0.00006275 Va r ( Y ) = 0.0000330625 + 0.0000007875 + 0.0000289 = 0.00006275
Standard Deviation:
S D ( Y ) = V a r ( Y ) = 0.00006275 ≈ 0.007921 SD(Y) = \sqrt{Var(Y)} = \sqrt{0.00006275} \approx 0.007921 S D ( Y ) = Va r ( Y ) = 0.00006275 ≈ 0.007921 S D ( Y ) ≈ 0.79 % SD(Y) \approx 0.79\% S D ( Y ) ≈ 0.79%
Coefficient of Variation:
C V ( Y ) = S D ( Y ) E ( Y ) = 0.007921 0.1115 ≈ 0.0710 CV(Y) = \frac{SD(Y)}{E(Y)} = \frac{0.007921}{0.1115} \approx 0.0710 C V ( Y ) = E ( Y ) S D ( Y ) = 0.1115 0.007921 ≈ 0.0710 or 7.10%
Comparing the Coefficient of Variation:
C V ( X ) = 13.25 % CV(X) = 13.25\% C V ( X ) = 13.25% C V ( Y ) = 7.10 % CV(Y) = 7.10\% C V ( Y ) = 7.10%
Since the coefficient of variation of asset Y is lower than asset X, asset Y is a better investment because it has lower relative risk compared to its expected return.