This year, Mrs. Fisher has 9 students who are new to the school. The number of new students
represents 7.5% of all her students. Which
equation could be used to determine x,
the total number of students Mrs. Fisher has
this year?
A
7.5
100
-
lx
B
7.5
9
х
100
С
х
7.5
9
100
D
D
7.5
100

Since the question is asking for the relative frequencies of the columns, we assume each row must add to 1.00. Divide the numbers in each row by the total of that row.
.. group 1, column A = 102/(102 +34) = 0.75
.. group 1, column B = 34/(102 +34) = 0.25

.. group 2, column A = 18/(18 +14) ≈ 0.56
.. group 2, column B = 14/(18 +14) ≈ 0.44