Answer:
year 7 mean: ≈7.714
year 8 mean: 14
Explanation:
mean = sum / number of observations
number of observations = 5, as there are 5 bars for each year
year 7 is the bar on the left for each day
observations for year 7:
5, 8, 9, 13, 19 (left to right)
sum = 5 + 8 + 9 + 13 + 19 = 54 for year 7
mean for year 7 = 54 / 7 ≈ 7.714
observations for year 8 (left to right):
10, 11, 18, 12, 19
sum = 10 + 11 + 18 + 12 + 19 = 70
mean = 70 / 5 = 14