High school students from grades 9–10 and 11–12 were asked to choose the kind of band to have play at a school dance: rap, rock, or country.
their choices were as follows:
grades 9–10—rap: 40; rock: 30; country: 55
grades 11–12—rap: 60; rock: 25; country: 35
find a correct two-way frequency table for the data

The correct two-way frequency table for the date will look like this:
                 
                               RAP      ROCK     COUNTRY     TOTAL
Grades 9-10           40           30            55                  125
Grades 11-12         60           25            35                  120
TOTAL                    100          55            90                  245

The sum of the row total is equal to the sum of the column total
125 + 120 = 100 + 55 + 90
245 = 245

The linear equation is: y=ax+b