Woman using the Urinella, a type of female urination device, to adapt to standard men's room urinals. A female urination device, female urination aid, or stand-to-pee device (STP) is a device which aids a female to urinate while standing upright. Variations include basic disposable funnels to more elaborate reusable designs. Female urination devices have increased in popularity since the 1990s.
Each of the rectangles in the histogram has a base of 25, and the heights are 3, 7, 8, 10, 1, and 1. Thus the total area of the histogram is 3x25+7x25+8x25+10x25+1x25+1x25=750. We want the value with area 750/2=375 to the right of it and 375 to the left of it.
The horizontal scale of the histogram is the range of tonal Levels from 0 to 255, making 256 in all. With 16-Bit images, which have many more tones, the histogram is still shown with the 256 levels. The vertical scale is the number of pixels at each level from 0 to the largest number (which can vary greatly).