This question is flawed. What if the new customers are all dissatisfied? What if only 22% or 2% are dissatisfied?
Let's assume none of the new customers are dissatisfied. Then you will need another 238 customers to bring down the persent of dissatisfied customers down to 4%. AND this is if exactly 8% of the original 238 customers were dissatisfied. The problem stated that at over 8% were dissatisfied. So the best one can say is that you need at least another 238 customers to bring down the percent to 4%