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 is a useful concept in statistics and is conceptually similar to the median. The first quartile is the data point at the 25 th percentile, and the third quartile is the data point at the 75 th percentile.