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.
For a set of data the three quartiles are values that divide the data up into four equally-populated groups. So the lower quartile, Q1, is a value such that one quarter of the data have a value below this.The upper quartile, Q3, is a value such that three-quarters of the data have a value below this.or a set of data the three quartiles are values that divide the data up into four equally-populated groups. So the lower quartile, Q1, is a value such that one quarter of the data have a value below this.