A researcher is interested in the effect on test scores of computer usage. Using school district data, she regresses district average test scores on the number of computers per student. What are possible sources of bias for whether p1 will be biased up or down , the estimated effect on tests scores of increasing the number of computers per student? For each source of bias below. determine 1. Average income per capita in the district If his variable is tetvill lklproduce a(an) bias of the estimated effect on test scores of Increasing the Vbias of the estimated effect on tests scores of increasing the number of computers per student.