Pull strength of soldered pins
When the vertical axis is 'frequency', the histogram for the left pins has a much bigger area than that for the right pins.
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.
In an evaluation of solder joints on printed circuit boards, 48 pins were soldered on the left side of circuit boards and a further 16 pins were soldered on the right side. The force (in pounds) required to pull each pin from its board after a period of 'environmental conditioning' was determined.
The pull strength of the left pins is higher (on average) than that of the right pins.