Question

   Ovservation   Portland   Houston   Jacksonville  
   1 85 71 64  
   2 75 75 69  
   3 82 73 67  
   4 76 74 74  
   5 71 69 80  

6 85 82 72

National Bearings manufactures bearings at plants located in Portland Oregon, Houston Texas, and Jacksonville Florida. To measure employee knowledge of Total Quality Management (TQM), six employees were randomly selected at each plant and tested. The test scores for these employees are given in DATA. Managers want to know if, on average, knowledge of TQM is equal across the 3 plants. Test equality of mean scores at Alpha = 0.05 .

What is the F value? p value? F critical value?

Do we reject equality mean or not? Is knowledge of TQM equal across all 3 plants or not?

  
                  

Answer 1

Using Minitab software, (Stat -> ANOVA -> One way), we get the following output :

Now,

The value of F test statistic = 3.42

P-value = 0.06

and critical value =

Since and P-value > 0.05, so we reject H₀ at 5% level of significance and we can conclude that there is no significant difference in means of knowledge of TQM among 3 plants.