The data in the accompanying table represent the compressive strength. in thousands of pounds per square inch (psi), of 20 samples of concrete taken two and seven days after a Click the icon to view the data table. a. At the 0.01 level of signicance, is there evidence that the mean strength is lower at two days than at seven days? Let p1 be the mean strength at two days and let p2 be the mean strength at seven days. State the null and altemalive hypotheses. Choose the correct answer below. @A. Ho: 20 (where on = P1 1:2) H1::RP0(where pD=u1p2) H1:pD 0 The test statistic is 15m = [3 (Round to two decimal places as needed.) 0 B. HozpDSO(wherepD=pf -p2) H1:pD>0 O D. H0: pD =0 (where on =p1 112) H1: pD #0 O F. \"03110