This range is followed by the second, third and fourth quartiles that grow incrementally larger. Find the middle value by locating the apex of central tendency on the graph. This will be the ...

The interquartile range is another measure of spread, except that it has the added advantage of not being affected by large outlying values. In order to calculate this value we must first ...

There are 40 babies in the table, so to find the lower quartile, find ¼ of 40, which is the 10th value. Reading from the graph, the lower quartile is 38. To find the upper quartile, find ¾ of 40 ...