Frequency Tables Relative 2 Way
Learning Target: Be able to identify and compute joint relative frequencies, marginal
relative frequencies, and conditional relative frequencies
*This is all about calculating percentages. So we divide numerators by denominators and
move the decimal 2 places to the right to make a percent.
Example: Maria surveyed her class and recorded the gender of 50 students who perferred
preferred dog, cats or other pets.
Complete this chart of a Two Way Frequency Table:
What does the “grand total” represent?
What does the number 28 represent in the last column represent?
What does the number 9 represent in the represent the frequency table?
Create Two-Way “Relative” Frequency Tables
Fill out the table again. This time turn each numbert ino a decimal by dividing each
number by the “grand total”.
Use the Two-Way “Relative” Frequency Table to find these frequencies
–Vocabulary
Joint Relatve Frequency = make a percent by dividing a number that is NOT in
the Total Column or Total Row by the Grand Total
–Example: What is the Joint Relatve Frequency of students surveyed who are boys and
profer cats as pets?
Marginal Relative Frequency = make a percent (fraction & %) by dividing a Row
Total or a Column Total that is on the “margin or edge” of the table by the Grand Total.
–Example: What is the Marginal Relative Frequency of students surveyed who are boys?
Conditional Relative Frequency = make a percent (fraction & %) by dividing a
number/frequency that is NOT on the Total Row or Total Columns (it is in the body of
the table) by the number/frequency of a Row Total or Column Total.
Example: Find the Conditional Relative Frequency that a student surveyed prefers cats as
pets, given that the student is a girl.
Example: Find the Conditional Relative Frequence that a student surveyed is a girl, given
that the student prefers cats as pets.