Answer:
755
Step-by-step explanation:
The sum of 308+622+381=755
You're assuming that this data set represents all of Mrs. Hassaan's pupils. Certain students could be missing from the histogram - for instance, there could be one or two students who missed the test, but for certain reasons will be taking a make-up exam. Their grade would not be recording in this data set, but they still contribute to the class size, and so would be unaccounted for here.
A: 0 3 4 5 5 6 7 9 9 20
3 3 5 5 6 8 8 9 9
B: No, they are not symmetric
