Chapter 7:  Data on compressive strength of concrete blocks in
100lb per square inch

       49.2 53.9 50.0 44.5 42.2 42.3 32.3 31.3 60.9 47.5
       43.5 37.9 41.1 57.6 40.2 45.3 51.7 52.3 45.7 53.7
       51.0 45.7 45.9 50.0 32.5 67.2 55.1 59.6 48.6 50.3
       45.1 46.8 47.4 38.3 41.5 44.0 62.2 62.9 56.3 35.8
       38.3 33.5 48.5 47.4 49.6 41.3 55.2 52.1 34.3 31.6
       38.2 46.0 47.0 41.2 39.8 48.4 49.2 32.8 47.9 43.3
       49.3 54.5 54.1 44.5 46.2 44.4 45.1 41.5 43.4 39.1
       39.1 41.6 43.1 43.7 48.8 37.2 33.6 28.7 33.8 37.4
       43.5 44.2 53.0 45.1 51.9 50.6 48.5 39.0 47.3 48.8