Tin has long been used in alloys with lead as solder, in amounts 5 to 70% w/w. Tin with lead forms a eutectic mixture at the weight proportion of 61.9% tin and 38.1% lead (the atomic proportion: 73.9%
The first quartile (Q 1) is defined as the middle number between the smallest number and the median of the data set.
Quartile deviation for Grouped Data. mbalectures June 15, 2010October 4, 2010 31 Comments. Quartile deviation or semi-interquartile range is the dispersion which shows the degree of spread around the middle of a set of data.