Answer:
[tex] z=\sqrt{80} [/tex]
Step-by-step explanation:
By geometric mean property:
[tex] y= \sqrt {16\times 4}[/tex]
[tex] y= \sqrt {64}[/tex]
[tex] y= 8[/tex]
By Pythagoras Theorem:
[tex] z=\sqrt{4^2 +8^2} [/tex]
[tex] z=\sqrt{16 + 64} [/tex]
[tex] z=\sqrt{80} [/tex]
