Answer:
[tex]\boxed{\text{It doubles}}[/tex]
Step-by-step explanation:
[tex]f(x)=4(2)^{x}[/tex]
Let's create a table of the values.
[tex]\begin{array}{lr}\mathbf{x} & \mathbf{f(x)} \\0 & 4 \\1 & 8 \\2 & 16 \\3 & 32 \\4 & 64 \\5 & 128 \\\end{array}\\\text{The number of people sharing the video $\boxed{\textbf{doubles}}$ every hour}[/tex]