Answer:
$0.40
Step-by-step explanation:
1st week total: 12.99 + 10.50 + 9.89 + 6.90 + 7.58 = $47.86
5 days total so the mean of 1st week: 47.86 / 5 = $9.57
2nd week, 2 more in total of 1st week = $47.86 + $ 2 = $49.86
The mean of 2nd week: 49.86 / 5 = $9.97
$9.97 - $9.57 = $0.40
2nd week increased 40 cents or $0.40