Answer: 24
Step-by-step explanation:
Given
[tex]2x^4+2y^4+2z^4=144[/tex]
dividing whole equation by 2, we get
[tex]\Rightarrow x^4+y^4+z^4=72[/tex]
Mean is given by the sum of the value of entities divided by the total no of entities
[tex]\Rightarrow \text{Mean}=\dfrac{x^4+y^4+z^4}{3}\\\\\Rightarrow \text{Mean}=\dfrac{72}{3}\\\\\Rightarrow \text{Mean}=24[/tex]