An article appeared in the Cement and Concrete Research Journal in the year 1989 investigates the compressive strength o
Posted: Sun Sep 05, 2021 5:04 pm
An article appeared in the Cement and Concrete Research Journal in the year 1989 investigates the compressive strength of concrete when mixed with fly ash. The compressive strength (in MPa) of nine samples in dry conditions on the twenty-eight day are as follows: 40.2, 30.4, 28.9, 30.5, 22.4, 25.8, 18.4, 14.2, and 15.3. The higher end of the 98% two-sided confidence interval on the mean compressive strength is: (2 points) 12.34 14.21 16.99 18.58 31.66 33.25 38.41 41.23 None of the above