The estimate of the mean garden area is 13.3 m²
What is the estimate of the mean garden area?
Total frequency = 100
Known frequency:
12 + 42 + 7 = 61
Unknown frequency = 100 - 61
= 39
20 < x ≤ 30 = m
30 < x ≤ 40 = n
If m = 2n
So,
m + n = 39
2n + n = 39
3n = 39
n = 39/3
n = 13
20 < x ≤ 30 = m
= 2n
= 2(13)
= 26
30 < x ≤ 40 = n
= 13
The mean garden area = {(12×5) + (42×15) + (26× 25) + (13×35) + (7×45)} /125
= (60+180+650+455+315) / 125
= 1,660/125
= 13.28
Approximately,
13.3 m²