1. **State the problem:**
We have a probability distribution with amounts won and their probabilities:
- Amounts: 0, -6a, 2
- Probabilities: 33%, 33%, 33%
We want to understand the expected value (mean) and possibly use the Z-score formula given as $$Z = \frac{x - \mu}{\sigma}$$ where $\mu$ is the mean and $\sigma$ is the standard deviation.
2. **Calculate the expected value $\mu$:**
The expected value is the sum of each amount multiplied by its probability.
$$\mu = 0 \times \frac{33}{100} + (-6a) \times \frac{33}{100} + 2 \times \frac{33}{100}$$
Simplify:
$$\mu = 0 - \frac{198a}{100} + \frac{66}{100} = -1.98a + 0.66$$
3. **Calculate the fraction multiplication:**
Given $$\frac{4}{12} \times \frac{1}{7}$$
Simplify numerator and denominator:
$$\frac{\cancel{4}}{\cancel{12}} \times \frac{1}{7} = \frac{1}{3} \times \frac{1}{7} = \frac{1}{21}$$
4. **Use the Z-score formula:**
Given $n=12$, and the formula $$Z = \frac{x - \mu}{\sigma}$$, you can calculate the Z-score for a value $x$ once $\mu$ and $\sigma$ are known.
Since $\sigma$ (standard deviation) is not provided, it cannot be calculated here.
**Final answers:**
- Expected value: $$\mu = -1.98a + 0.66$$
- Fraction multiplication: $$\frac{4}{12} \times \frac{1}{7} = \frac{1}{21}$$
Expected Value F93De1
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