Solution and Explanation:
The given data is as follows:
Error rate = 4%, per hour payment of inspector = $8, inspection of units = at the rate of 49 per hour, cost = $9 per unit
The problem can be solved as considering an opportunity to have an improvement of 4% in the quality.
In case inspector is not hired then it will cost .04 multiply 9= $.3.6 per unit and in case the inspector is hired it will cost $ 0.163 approx.(8 divided by 49).
Therefore, on comparison, it is recommended to hire the inspector.