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.
What are the quartiles. The first quartile, or 25th percentile xL (also written as Q1), is the number for which 25% of values in the data set are smaller than x L. The second quartile or 50th percentile, xm (also written as Q2) is also known as the median.