Question
O retorno mensal de certo investimento de risco pode ser modelado pela variável aleatória W, com função de probabilidade dada a seguir. mathrm(W) & -5 % & 0 % & 5 % & 10 % & 15 % mathrm(P)(mathrm(W)=mathrm(w)) & 0,4 & 0,15 & 0,25 & 0,15 & 0,05 O retorno esperado é: A -0,5 % . B 0,5 % . C 1,5 % . D 5 % . E 7,5 % .
Solution
4.6
(356 Votos)
Teresa
Mestre · Tutor por 5 anos
Resposta
### C
Explicação
## Step 1: Understand the Problem### We are given a probability distribution for the monthly return
of a risky investment. The table provides possible returns and their associated probabilities. We need to calculate the expected return.## Step 2: Define the Expected Value Formula### The expected value \( E(W) \) of a discrete random variable is calculated using the formula:
where
are the possible values of
, and \( P(W = w_i) \) are their respective probabilities.## Step 3: Apply the Values from the Table### Using the values from the table:-
, \( P(W = -5\%) = 0.4 \)-
, \( P(W = 0\%) = 0.15 \)-
, \( P(W = 5\%) = 0.25 \)-
, \( P(W = 10\%) = 0.15 \)-
, \( P(W = 15\%) = 0.05 \)## Step 4: Calculate the Expected Return### Substitute these values into the expected value formula:
### Simplify each term:-
-
-
-
-
### Sum these results: