Can someone help me understand the step-by-step process to solve this?

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

	High School	Bachelor	Graduate	TOTAL
Public Broadcasting	50	150	80	280
Commercial Stations	150	250	120	520
TOTAL	200	400	200	800

What is the test statistic?

The null hypothesis is to be tested at the 5% level of significance; therefore what is the critical value for this test?

What is the p-value?