Suppose the cumulative distribution function of the random variable [tex]\(X\)[/tex] is given by:

[tex]\[
F(x) = \left\{
\begin{array}{cc}
0 & x \ \textless \ 0 \\
0.2x & 0 \leq x \ \textless \ 5 \\
1 & x \geq 5
\end{array}
\right.
\][/tex]

Determine the following (do not round):



Answer :

Let's analyze the given cumulative distribution function [tex]\(F(x)\)[/tex] of the random variable [tex]\(X\)[/tex] and determine its values at various specified points. The function is defined as:

[tex]\[ F(x) = \begin{cases} 0 & \text{if } x < 0 \\ 0.2x & \text{if } 0 \leq x < 5 \\ 1 & \text{if } 5 \leq x \end{cases} \][/tex]

We'll determine [tex]\( F(x) \)[/tex] at [tex]\( x = -1, 0, 2.5, 5, \)[/tex] and [tex]\( 6 \)[/tex].

1. For [tex]\( x = -1 \)[/tex]:
- Since [tex]\( -1 < 0 \)[/tex], we use the first case of the function.
[tex]\[ F(-1) = 0 \][/tex]

2. For [tex]\( x = 0 \)[/tex]:
- Since [tex]\( 0 \leq 0 < 5 \)[/tex], we use the second case of the function.
[tex]\[ F(0) = 0.2 \cdot 0 = 0 \][/tex]

3. For [tex]\( x = 2.5 \)[/tex]:
- Since [tex]\( 0 \leq 2.5 < 5 \)[/tex], we use the second case of the function.
[tex]\[ F(2.5) = 0.2 \cdot 2.5 = 0.5 \][/tex]

4. For [tex]\( x = 5 \)[/tex]:
- Since [tex]\( 5 \leq x \)[/tex], we use the third case of the function.
[tex]\[ F(5) = 1 \][/tex]

5. For [tex]\( x = 6 \)[/tex]:
- Since [tex]\( 6 \geq 5 \)[/tex], we use the third case of the function.
[tex]\[ F(6) = 1 \][/tex]

In summary, the values of the cumulative distribution function at the specified points are:

[tex]\[ \left( F(-1), F(0), F(2.5), F(5), F(6) \right) = (0, 0, 0.5, 1, 1) \][/tex]