Can we infer from the data that the proportion of Americans earning at least $75,000 is greater

Question:

Can we infer from the data that the proportion of Americans earning at least $75,000 is greater in 2008 than in 2006 (INCOME06)?
For each of the following variables, conduct a test to determine whether Democrats and Republicans (PARTY 1 = Democrat, 3 = Republican) differ in their correct answers.