Students are randomly assigned to three reading classes. Each class is taught by a different method. At the end of the course, a comprehensive reading examination is given, and the results are shown below.

Class A	Class B	Class C
87	82	97
92	78	90
61	41	83
83	65	92
47	63	91

At =0.05=0.05, what is the critical value for the calculated F ?