Final answer:
To find the value of XZ, use the Triangle Inequality Theorem and set up an equation: XY + YZ > XZ. Simplify the equation to find that XZ must be greater than 18.2.
Step-by-step explanation:
To find the value of XZ, we need to use the fact that Y is between X and Z. We also have the lengths of XY and YZ. Let's represent the unknown value of XZ as 'a'. We can use the Triangle Inequality Theorem to set up an equation: XY + YZ > XZ.
Plugging in the given values, we get: 5.8 + 12.4 > a. Simplifying this equation, we find that XZ must be greater than 18.2. Therefore, the value of XZ is greater than 18.2.