1. An advertising executive wants to determine if there is a relationship between a person's political bent and level of education. He takes a random sample of people and sorts them according to the highest level of education completed. Based on the results in the contingency table below, test at a 0.025 level of significance if one's political preference is independent of one's educational level.

Observed Frequencies

CollegeHigh SchoolGrade School

Liberal170160 75

Conservative9011095