Expected Value 18A278
1. **State the problem:** We have a discrete random variable $X$ representing the number of patients visiting a clinic each day with probabilities:
$$P(0) = 0.2, \quad P(1) = 0.3, \quad P(2) = 0.5$$
We want to find the expected value (mean) of $X$, denoted $E(X)$.
2. **Formula for expected value:** For a discrete random variable,
$$E(X) = \sum_{i} x_i P(x_i)$$
where $x_i$ are the possible values and $P(x_i)$ their probabilities.
3. **Apply the formula:**
$$E(X) = 0 \times 0.2 + 1 \times 0.3 + 2 \times 0.5$$
4. **Calculate each term:**
$$0 \times 0.2 = 0$$
$$1 \times 0.3 = 0.3$$
$$2 \times 0.5 = 1.0$$
5. **Sum the terms:**
$$E(X) = 0 + 0.3 + 1.0 = 1.3$$
6. **Interpretation:** The expected number of patient visits per day is $1.3$. This means on average, about 1.3 patients visit the clinic daily.