Concrete cube test. The following 28-day compressive strengths, in newtons per
square millimeter, were obtained from test results on concrete cubes in England:50.5, 45.8, 49.6, 47.7, 54.0, 49.4, 54.1, 53.1, 56.5, 55.2, 52.7, 52.0, 54.2, 55.2, 53.4,
51.0, 53.1, 48.5, 51.0, 58.6, 52.5, 49.5, 51.1, 48.1, 50.2, 49.3, 47.3, 52.9, 52.8, 49.5,
48.8, 53.8, 47.3, 47.7, 52.2, 45.7, 53.4, 48.5, 49.1, 43.3
The data were supplied by Dr J. E. Ash, University of Birmingham, England.
Compare these results with the compressive strengths in Table E.1.2 by drawing
back-to-back stem-and-leaf plots. For this purpose, plot the foregoing results on the
left of the stem with reference to Fig. 1.3.1 and omit the cumulative frequencies.
Comment on the differences in the distributions.