Answer
There are more trees in group 1 compared to group 2 and 3. This is because group 1 has the highest mean.
Work Step by Step
Group means of the stem and leaf plots
Group 1
16+19+19+20+21+22+24+27+27+28+29+33=285
285/12=23.750
Group 2
2+9+12+12+14+14+15+17+17+18+19+20=169
169/12=14.083
Group 3
4+12+12+15+18+18+19+22+22=142
142/9=15.778