In a study comparing means of 4 groups, the F ratio was significant at the p<.05 level. The 4 means are Mean 1=13.12; Mean 2=9.31; Mean 3=13.65; and Mean 4=11.34. Tukey's post hoc comparison is used to test which means statistically differ from each other. The obtained HSD value at the p=.05 level is 3.74. Which means are statistically significantly different from each other? Explain.