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.
Interquartile range. The interquartile range is another range used as a measure of the spread. The difference between upper and lower quartiles (Q 3 âQ 1), which is called the interquartile range, also indicates the dispersion of a data set.The interquartile range spans 50% of a data set, and eliminates the influence of outliers because, in effect, the highest and lowest quarters are removed.emi-quartile range. The semi-quartile range is another measure of spread. It is calculated as one half the difference between the 75th percentile (often called Q 3) and the 25th percentile (Q 1). The formula for semi-quartile range is: (Q 3 âQ 1) Ã· 2.