1. Relations in Categorical Data
To analyze categorical data, percents or counts of individuals that fall into various categories are used
A two-way table is a format of comparing two categorical variables.
The row variable/column variable refers to the variable displayed respectively.
Marginal distributions are the distributions of each variable separately that appear at the right and bottom margins.

2. Years of school completed, by age (in thousands of persons)
Age group
Ed. 25 to to Total
No H.S. 5, ,152 16,035 30,512
H.S. 14,061 24,070 18,320 56,451
1,3 yrs 11,659 19, ,662 41,247
4+ yrs 10,342 19, ,005 38,225
Total 41,388 73,028 52, ,438
roundoff error can often occur with large #’s