Print ASCII histogram
APL 66 51
' *'[1+(⌽⍳b)∘.≤v←+/(⍳b)∘.=⌈x[⍋x]÷(⌈/x←1↓v)÷b←↑v←⍎⍞]

Using the example I quoted in my comment on the question where the bin size is 2.25:
4 1 1 2 2 5 8 9 6 3

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