1. The problem asks to determine the y-value of a step function when $x=4$. 2. The function is a step function defined piecewise with constant values on intervals: - From $0 < x \leq 2$, $y=1$ - From $2 < x \leq 4$, $y=2$ - From $4 < x \leq 6$, $y=4$ - From $6 < x \leq 8$, $y=6$ - From $8 < x \leq 10$, $y=8$ 3. Important rule for step functions: the value at the boundary depends on whether the interval includes the endpoint (solid dot) or excludes it (open circle). 4. At $x=4$, the graph shows a solid dot at $(4,2)$ and an open circle at $(4,4)$, meaning the function value at $x=4$ is $y=2$. 5. Therefore, the y-value of the function when $x=4$ is: $$y=2$$ This is because the function value at the closed endpoint of the interval $2 < x \leq 4$ is $2$, and the next interval $4 < x \leq 6$ starts just after 4 with $y=4$. Final answer: $y=2$ when $x=4$.