The least amount that we could pay is that when we choose a DJ for $219 and light show for $159. This totals to $378.
Then, solving for the maximum amount that we could pay. That is, the DJ is $369 and the light is $309 which totals to $678. All other possible amounts are in between these values such that the inequality that would best represent the scenario is,
378 ≤ x ≤ 678