Exercise 1: WIP=4, Verified Against Little's Law — Possible Solution
====================================================================

RESULT
------------------------------
    WIP=4: total_time=797, avg_cycle_time=158.7

    Little's Law prediction (WIP / throughput):
      throughput = 20 / 797 = 0.02509 items/min
      predicted cycle time = 4 / 0.02509 = 159.4

    Predicted: 159.4, Measured: 158.7

The measured cycle time (158.7) matches Little's Law's own prediction
(159.4) within less than 1% - consistent with the small deviations the
chapter's own table showed at every other WIP level tested.

WHY THIS WORKS AS AN ANSWER
------------------------------
This extends the chapter's own verification to a WIP level it didn't
explicitly test, confirming the relationship isn't a coincidence of
the specific values chosen (2, 3, 5, 10, 20) - it holds at WIP=4 too,
with the same small, consistent margin of error the chapter's own
table showed elsewhere (a rounding/boundary effect from the simulation
processing whole-minute steps, not a flaw in Little's Law itself,
which is an idealized long-run average).