You seem to have omitted "the table below", so we can't tell whether your stem and leaf plot (not "leaf and plot system"!) is correct.
But you don't show 20 leaves, unless some things I take to be commas are meant to be 1. And your key indicates that the numbers are not whole numbers, but are numbers like 12.2. I don't want to see such a classroom!
Or is the work you refer to what is on the bottom half of the page?? You do show 20 numbers there; but your key says they are percentages, not numbers of students. Furthermore, there are 20 classes; how can there be 20 students total? I think you counted classes rather than students (which you would do by adding the numbers in each class, probably from the original data rather than from the plot).
Please show us the entire problem, including all the data, and be sure that your work is clearly readable and identified.