Suppose that the discrete random variable X has cumulative distribution function given by if x < 1 if 1

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### Cumulative Distribution Function of a Discrete Random Variable

Given a discrete random variable \(X\), the cumulative distribution function \(F(x)\) is defined as follows:

\[ F(x) = \begin{cases} 
0, & \text{if } x < 1 \\ 
\frac{1}{3}, & \text{if } 1 \leq x < \frac{4}{3} \\ 
\frac{1}{2}, & \text{if } \frac{4}{3} \leq x < \frac{3}{2} \\ 
\frac{3}{4}, & \text{if } \frac{3}{2} \leq x < \frac{9}{5} \\ 
1, & \text{if } x \geq \frac{9}{5} 
\end{cases}
\]

### Task:
Find the possible values and the probability mass function (PMF) of \(X\).

**Solution:**

To find the possible values and the PMF, we need to compute the differences in the cumulative distribution values, as those differences represent the probabilities at specific points.

1. **Calculate the Differences:**

    For each interval, the difference in \(F(x)\) indicates the probability mass at the respective value of \(x\):

    - For \( x = 1 \): \( P(X = 1) = F\left(\frac{4}{3}\right) - F(1) = \frac{1}{2} - \frac{1}{3} = \frac{1}{6} \)
    - For \( x = \frac{4}{3} \): \( P(X = \frac{4}{3}) = F\left(\frac{3}{2}\right) - F\left(\frac{4}{3}\right) = \frac{3}{4} - \frac{1}{2} = \frac{1}{4} \)
    - For \( x = \frac{3}{2} \): \( P(X = \frac{3}{2}) = F\left(\frac{9}{5}\right) - F\left(\frac{3}{2}\right) = 1 - \frac{3}{4} = \frac{1}{4} \)
    - For \( x \geq \frac{9}{
Transcribed Image Text:### Cumulative Distribution Function of a Discrete Random Variable Given a discrete random variable \(X\), the cumulative distribution function \(F(x)\) is defined as follows: \[ F(x) = \begin{cases} 0, & \text{if } x < 1 \\ \frac{1}{3}, & \text{if } 1 \leq x < \frac{4}{3} \\ \frac{1}{2}, & \text{if } \frac{4}{3} \leq x < \frac{3}{2} \\ \frac{3}{4}, & \text{if } \frac{3}{2} \leq x < \frac{9}{5} \\ 1, & \text{if } x \geq \frac{9}{5} \end{cases} \] ### Task: Find the possible values and the probability mass function (PMF) of \(X\). **Solution:** To find the possible values and the PMF, we need to compute the differences in the cumulative distribution values, as those differences represent the probabilities at specific points. 1. **Calculate the Differences:** For each interval, the difference in \(F(x)\) indicates the probability mass at the respective value of \(x\): - For \( x = 1 \): \( P(X = 1) = F\left(\frac{4}{3}\right) - F(1) = \frac{1}{2} - \frac{1}{3} = \frac{1}{6} \) - For \( x = \frac{4}{3} \): \( P(X = \frac{4}{3}) = F\left(\frac{3}{2}\right) - F\left(\frac{4}{3}\right) = \frac{3}{4} - \frac{1}{2} = \frac{1}{4} \) - For \( x = \frac{3}{2} \): \( P(X = \frac{3}{2}) = F\left(\frac{9}{5}\right) - F\left(\frac{3}{2}\right) = 1 - \frac{3}{4} = \frac{1}{4} \) - For \( x \geq \frac{9}{
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