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SECTION 13 / 28
Run the source’s exact positional grade rule
REAL COURSE DATA · SORT, GROUP AND VERIFY
Assign and compare grade policies
Follow the selected procedure. Change a field, tie rule or weekday and explain why the result changes.
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Predict the next change. Keep track of which list level, field and position convention the procedure uses.
q4 = length(L)/4
q3 = length(L)/2
q2 = 3*length(L)/4
A=[]; B=[]; C=[]; D=[]
position = 0
foreach Pair in L: # L is ascending by marks
if position > q2: A = A ++ [first(Pair)]
if position > q3 AND position <= q2: B = B ++ [first(Pair)]
if position > q4 AND position <= q3: C = C ++ [first(Pair)]
if position <= q4: D = D ++ [first(Pair)]
position = position + 1
return [A,B,C,D]Read the comparisons literally. For 30 students the boundaries are 7.5,15,22.5. Starting at position 0 gives D at 0–7, C at 8–15, B at 16–22 and A at 23–29. Do not silently round thresholds or replace zero-based positions with one-based counts.
This is the source’s SIMPLE positional procedure, not the hand-adjusted classroom grouping and not a universal statistical quantile convention. Its purpose is to demonstrate sorting, positions and a four-list result. The groups are approximate quarters and can split equal marks.
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Which grade gets position 15 under this exact code?
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C, because position ≤ q3 and position > q4. B requires position > 15.
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How many A students does this code produce for 30 records?
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7: zero-based positions 23 through 29.
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Why not claim all four groups have exactly 7.5 students?
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Student counts are integers. Exact comparisons determine which positions enter each group.