26 The data below represent the compressive strength, in thousands of pounds per square inch (psi), of 40 samples of concrete taken two and seven...

10.26 The data below represent the compressivestrength, in thousands of pounds per square inch (psi), of 40 samples of concrete taken two and seven days after pouring.a. At the 0.01 level of significance, is there evidence thatthe mean strength is lower at two days than at sevendays?b. What assumption is necessary about the population distributionin order to perform this test?c. Find the p-value in (a) and interpret its meaning.SampleTwo Days Seven Days3.5052