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.
In statistics, quartiles are three points that divide the data set into four equal groups. Each group represents the one-fourth of the data set. First quartile (Q 1), also known as lower quartile, splits the lower 25% of data. It is the middle value of lower half. Second quartile (Q 2) which is more commonly known as median splits the data in half (50%). Median divides the data into a lower half and an upper half. Third quartile (Q 3), also known as upper quartile, splits lowest 75% (or highest 25%) of data.