The paper “Slender High-Strength RC Columns Under Eccentric Compression” (Magazine of Concrete Res., 2005:

361–370) gave the accompanying data on cylinder strength

(MPa) for various types of columns cured under both moist conditions and laboratory drying condition

a. Estimate the difference in true average strength under the two drying conditions in a way that conveys information about reliability and precision, and interpret the estimate.
What does the estimate suggest about how true average strength under moist drying conditions compares to that under laboratory drying conditions?

b. Check the plausibility of any assumptions that underlie your analysis of (a).