Archie and Callum decided to have a competition. They both played their favourite computer game four times over the weekend. Archie scored:

521 495 539 522

At break time they compared their scores and Callum told him that he scored 15 points more than Archie.

What was Callum’s mean average score?

To find Callum's mean average score, we need to first calculate the total score he achieved over the four games.

Since Archie's scores were 521, 495, 539, and 522, his total score is:

521 + 495 + 539 + 522 = 2077

Callum scored 15 points more than Archie, so his total score is:

2077 + 15 = 2092

To find Callum's mean average score, we divide his total score by the number of games played (4):

2092 / 4 = 523

Therefore, Callum's mean average score is 523.