Janet wanted to understand whether grade level had any relationship to their opinion on extending the school day. she surveyed some students and displayed the results in the table below: in favor opposed undecided grade 9 4 2 8 grade 10 7 11 8 grade 11 14 15 9 grade 12 11 5 10 compare p(grade 9 | opposed) with p(opposed | grade 9).

Grade       In Favor     Opposed     Undecided          Total
9                 4                   2                    8                   14
10               7                  11                   8                    26
11               14                 15                  9                    38
12               11                 5                    10                  26
Total           36                 33                   35                 104

Above is a partial sum chart that will help us in our quest.

P(Grade 9 | opposed)
The probability of Grade 9, given opposed, is the portion of opposed students that are in grade 9. 
Total number opposed: 33
Number opposed in Grade 9: 2
P(Grade 9 | opposed) = 2 / 33 = 0.06

P(opposed | Grade 9)
Total Number Grade 9: 14
Number opposed in Grade 9: 2
P(opposed | Grade 9) = 2 / 14 = 0.14