Answer:
He needs to sell at least 49 mugs.
Step-by-step explanation:
Since Ronny earned $228 and needs to earn more than $372, he needs to earn more than 372-228 = 144.
Since he sells a mug for $3 and needs more than $144, his earning must be greater than 144:
→ 3x > 144, x represents the number of coffee mugs
→ x > 48
→ x must be at least 49