There are three quartiles. The first or lower quartile (LQ) of a list is a number (not necessarily a number in the list) such that at least 1/4 of the numbers in the list are no larger than it, and at least 3/4 of the numbers in the list are no smaller than it. The second quartile is the median. The third or upper quartile (UQ) is a number such that at least 3/4 of the entries in the list are no larger than it, and at least 1/4 of the numbers in the list are no smaller than it. To find the quartiles, first sort the list into increasing order. Find the smallest integer that is at least as big as the number of entries in the list divided by four. Call that integer k. The kth element of the sorted list is the lower quartile. Find the smallest integer that is at least as big as the number of entries in the list divided by two. Call that integer l. The lth element of the sorted list is the median. Find the smallest integer that is at least as large as the number of entries in the list times 3/4. Call that integer m. The mth element of the sorted list is the upper quartile.