Weights of newborn calves

When the vertical axis is 'frequency', the histogram for the Friesians has a much bigger area than that for the Angus calves since there are many more of them.

Select Relative frequency from the pop-up menu. This standardises the two histograms to make their areas equal and therefore makes it easier to compare the distributions.

As part of a study of newborn calves at the author's university, a researcher recorded their birth weights. The calves were of two breeds, Friesian and Angus.

With relative frequencies, it is easier to see that a higher proportion of Angus calves have weights between 34 and 40 kg than the corresponding proportion of Friesian calves, and a higher proportion of Friesians have weights over 40 kg.