Assuming that there is no effect on movie length from the interaction between star rating and CTR rating, test the null hypothesis that star rating has no effect on movie length. Identify the test statistic and critical value, and state the conclusion. Use a 0.05 significance level.
Exercises 7 and 8 refer to the sample data in the following table and the corresponding Excel display. The table entries are the numbers of support beams manufactured by four different operators using each of three different machines. In the Excel results, the operators are represented by rows and the machines are represented by columns.
Machine 
1 
2 
3 
1 
66 
74 
67 
2 
58 
67 
68 
3 
65 
71 
65 
4 
60 
64 
66