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.
Quartiles. Quartiles are the values that divide a list of numbers into quarters. 1  First put the list of numbers in order. 2  Then cut the list into four equal parts. 3  The Quartiles are at the cuts.