A random sample of five observations from three normally distributed populations produced the following data: (You may find it useful to reference the F table .) x A = 24.8 a. Calculate the grand mean. (Round final answer to 4 decimal places.) b. Calculate SSTR and MSTR . (Round final answers to 4 decimal places.) c. Calculate SSE and MSE . (Round final answers to 4 decimal places.) d. Specify the competing hypotheses in order to determine whether some differences exist between the population means. H 0 : A = B = C ; H A : Not all population means are equal. H 0 : A B C ; H A : Not all population means are equal. H 0 : A B C ; H A : Not all population means are equal. e-1. Calculate the value of the F ( df 1 , df 2 ) test statistic. (Round final answer to 3 decimal places.) .