Answer:
K must be in range $45000 ≤ k ≤ $53000 to make this an effective screening device.
Step-by-step explanation:
In order for the screening device to be effective, the range of k must be such that, it is more than the pay of a worker without diploma. The extra amount must at least be equal to the cost of diploma
So the value of k must be in range from (35000 + 10000) to (35000 + 18000)
Hence,
$45000 ≤ k ≤ $53000