Answer:
278
Explanation:
average = sum/count
count = 7 (7 days)
monday = 150
tuesday = 250
wednesday = 200
thursday = 250
friday = 350
saturday = 450
sunday = 300
sum = 150 + 250 + 200 + 250 + 350 + 450 + 300 = 1950
mean = 1950/7 = 278.571428571 ≈ 278