data tanaman tomat = 15cm=2, 16cm=5, 17cm=2, 20cm=3, 21cm=2, 25cm=4, 27cm=2. tanaman tomat yg memiliki tinggi dibawah rata-rata ada berapa

total = 
(15x2) + (16x5) + (17x2) + (20x3) + (21x2) + (25x4) + (27x2)
= 30 + 80 + 34 + 60 + 42 + 100 + 54
=  400

jumlah tanaman = 2 + 5 + 2 + 3 + 2 + 4 + 2 = 20
rata rata = 400 : 20 = 20

dibawah rata rata
= 2 + 5 + 2
= 9