307 diamonds were sampled and randomly sorted into three groups of diamonds. These diamonds were randomly assigned to one of the three organizations, or groups (HRD, GIA, or IGI), that certify the appraisal of diamonds. A study was conducted to determine if the average size of diamonds reported by these three certification groups differ. A completely randomized design was used and the resulting ANOVA table is shown below.
One-Way AOV for CARAT by CERT
Source DF SS MS F P
CERT 2 8.3265 4.16326 83.21 0.0000
Error 305 15.2604 0.05003
Total 307 23.5869
Give a practical conclusion for the test in the words of the problem. Use α = 0.10 to make your conclusion.
◦ There is sufficient evidence to indicate that the mean carat weight for the GIA group is lower than the other two groups.
◦ There is insufficient evidence to indicate that differences exist among the mean carat weights for the three certification groups.
◦ There is sufficient evidence to indicate that the mean carat weight for the HRD group equals the mean carat weight for the IGI group.
◦ There is sufficient evidence to indicate that differences exist among the mean carat weights for the three certification groups.
Diamonds
Reference Groups
The Distribution of Dominant and Minority Groups
Common Nonsilicate Mineral Groups
Groups of Elephants
Estimates of the dates of origin and extinction of the three main groups of hominins (green, blue, a