Step-by-step explanation:
Is this the full question
Answer:

Step-by-step explanation:
Quadratic function is given as 
Let's find a, b and c:
Substituting (0, 6):



Now that we know the value of c, let's derive 2 system of equations we would use to solve for a and b simultaneously as follows.
Substituting (2, 16), and c = 6








=> (Equation 1)
Substituting (3, 33), and c = 6








=> (Equation 2)
Subtract equation 1 from equation 2 to solve simultaneously for a and b.


Replace a with 4 in equation 2.
The quadratic function that represents the given 3 points would be as follows:



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.