I don't understand how the Stanford 10 achievement total battery percentile rank statistically "sums" from the component test percentile ranks. My son appeared to score in the 98th percentile in total reading, 99th percentile in total math, aced the rest of the test, but his total battery percentile is only 93rd....all I can tell from this is he is somewhere between 93rd and 99th (I think)...I have had a few stats classes in college/post grad...this doesn't make sense or I am not reading it right. Please help decipher this for me.
In detail, here are my son's 1st Grade Stanford 10 Achievement Test Scores:
Total Reading: 89/90, Nat'l PR-S = 98-9, Nat'l NCE = 93.3
Total Math: 49/50, Nat'l PR-S = 99-9, Nat'l NCE = 99.0
Language: 30/30, Nat'l PR-S = 98-9, Nat'l NCE = 93.2
Spelling: 30/30, Nat'l PR-S = 89-8, Nat'l NCE = 75.8
Environment: 30/30, Nat'l PR-S = 99-9, Nat'l NCE = 99.0
Total Battery: 228/230, Nat'l PR-S = 93-8, Nat'l NCE = 80.9
PR-S = percentile rank-stanine
NCE = normal curve equivalent
