From a Poll of 800 Television Viewers, the Following Data

From a poll of 800 television viewers, the following data have been accumulated as to their levels of education and their preference of television stations. We are interested in determining if the selection of a TV station is independent of the level of education.
Educational Level

$\begin{array}{rrrrr}&\text { High School } & \text { Bachelor } &\text { Graduate }& \text { TOTAL }\\\text { Public Broadcasting } & 50 & 150 & 80 & 280 \\\text { Commercial Stations } & 150 & 250 & 120 & 520\\\text { TOTAL } & 200 & 400 & 200 & 800\end{array}$
a. State the null and the alternative hypotheses.
b. Show the contingency table of the expected frequencies.
c. Compute the test statistic.
d. The null hypothesis is to be tested at 95% confidence. Determine the critical value for this test.
e. Determine the p-value and perform the test.