An engineer wants to know if the mean strengths of three different concrete mix designs differ significantly. He randomly selects 9 cylinders that measure 6 inches in diameter and 12 inches in height in which mixture A is poured, 9 cylinders of mixture B, and 9 cylinders of mixture C. After 28 days, he measures the strength (in pounds per square inch) of the cylinders. The results are presented in the accompanying table. Eff Click the icon to view the data table. O A. Ho: at least one of the means is different and H, : HA = HB = Pc OB. Ho: HA = HB = Hc and H1 : HA HE Hc O C. Ho: HA = HB = Hc and H1: at least one of the means is different O D. Ho: HA = Up and Hy: the means are different (b) Explain why we cannot use one-way ANOVA to test these hypotheses. Choose the correct answer below. O A. Because the samples are not random. O B. Because the samples are not independent of each other. O C. Because populations are not normally distributed. O D. Because the standard deviation for mixture B is more than two times larger than the standard deviation for mixture A.