<p>The ACT is not "graded on a curve". Go here: <a href="http://www.actstudent.org/testprep/index.html%5B/url%5D">http://www.actstudent.org/testprep/index.html</a> and look at the pdf "Preparing for the ACT". On page 63 is a table for converting raw scores to standard scores for the practice test in that booklet. Each test form has a table that looks like this. The values are different depending on how hard the test is. The conversion table is determined once for each test form by administering it and a test form of "known" difficulty to equivalent populations at the same time. If they do better on the new test, then the new test is likely easier, so they make the conversion harder so that the two tests are equivalent. It has nothing to do with percentiles. This all happens long before that test form is administered to you. So it's possible that, for example, no one would get a 36 in English for a particular test date if no one got all the English questions right. They do NOT curve it so that those who only missed one question get a 36, unless the conversion table was set up that way in the first place.</p>
<p>The percentile rank table Diane directs you to is created each year. It is based on testers from LAST school year (04-05) or maybe last year and the two previous years. So if you score in the 75th percentile, it means that 75 percent of last year's testers got your score or lower. It has nothing to do with the population you test with.</p>
<p>strok3s, the composite range you mention is probably for the middle 50 percent. That means that if you ignore the bottom quarter and the top quarter of Cornell students, the remaining students scored 27-30.</p>