Recent content by ACHQ

Ok I get everything except for one thing... Why is the variance of each sum equal to : 0.27^2, 0.27^2, 0.46^2 respectively (i.e. why is the variance equal to the %weight squared?) Thanks!

So if the college's admission criteria were: 27% GPA, 27% Standardized test, 46% Supplementary application (again all have been Z-scored individually), would the same formula still apply, except instead of the variance being 0.54^2 + 0.46^2 = 0.5032 (stdev = 0.7094). It would be 0.27^2 + 0.27^2...

The linear assumption isn't really correct. The reason being is that they normalize both the GPA and the Supp to Z scores and then take the top ~15% of the "weighted average score". uart seems to be on the right track, I myself couldn't figure out the math behind it, but that number 92-93rd...

SO the entrance to a college is based off of two factors: 54% grade point average, and 46% supplemental application. Both factors are standardized by the college using a z-score. If a student is ranked in the only ~55 percentile for his grade point average, what percentile rank...