Total number of rounds = 4
Score in each round, as written below:
Round 1: -2
Round 2: -6
Round 3:-7
Round 4: -3
Total score across rounds = (-2) + (-6) + (-7) + (-3)
⇒ Total score across rounds = -18
Mean score per round = Total score across rounds ÷ Total rounds
⇒ Mean score per round = -18 ÷ 4
⇒ Mean score per round = -4.5
Hence, the golfer's mean score per round was -4.5
