Question: According to an Ipsos poll, the perception of unfairness in the U.S. tax code is spread fairly evenly across income groups, age groups, and education levels. In an April 2006 survey of 1,005 adults, Ipsos reported that almost 60% of all people said the code is unfair, whereas slightly more than 60% of those making more than $50,000 viewed the code as unfair (“People Cry Unfairness, “The Cincinnati Enquirer, April 16, 2006, p. A8). Suppose that the following contingency table represents the specific breakdown of responses:

Income Level

U.S. Trade Less than More than Total

Code $50,000 $50,000 ____________

Fair 225 180 405

Unfair 280_ 320_ 600_

Total 505 500 1,005

a. Given that a respondent earns less than $50,000, what is the probability that he or she said that the tax code is fair?

b. Given that a respondent earns more than $50,000, what is the probability that he or she said that the tax code is fair?

c. Is income level independent of attitude about whether the tax code is fair? Explain.