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. One of the four divisions of observations which have been grouped into four equal-sized sets based on their statistical rank. The quartile including the top statistically ranked members is called the first quartile and denoted. The other quartiles are similarly denoted, , and. For data points with of the form (for, 1, ...), the hinges are identical to the first and third quartiles. The following table summarizes a number of common methods for computing the position of the first and third quartiles from a sample size (P. Stikker, pers.