' FB 1.05.0 Win64

Dim letters  (0 To 7) As String = {"aleph", "beth", "gimel", "daleth", "he", "waw", "zayin", "heth"}
Dim actual   (0 To 7) As Integer '' all zero by default
Dim probs (0 To 7)    As Double = {1/5.0, 1/6.0, 1/7.0, 1/8.0, 1/9.0, 1/10.0, 1/11.0}
Dim cumProbs (0 To 7) As Double

cumProbs(0) = probs(0)
For i As Integer = 1 To 6
  cumProbs(i) = cumProbs(i - 1) + probs(i)
Next
cumProbs(7) = 1.0
probs(7) = 1.0 - cumProbs(6)

Randomize
Dim rand As Double
Dim n As Double = 1000000
Dim sum As Double = 0.0

For i As Integer = 1 To n
  rand = Rnd  '' random number where 0 <= rand < 1
  Select case rand
    Case Is <= cumProbs(0)
      actual(0) += 1
    Case Is <= cumProbs(1)
      actual(1) += 1
    Case Is <= cumProbs(2)
      actual(2) += 1
    Case Is <= cumProbs(3)
      actual(3) += 1
    Case Is <= cumProbs(4)
      actual(4) += 1
    Case Is <= cumProbs(5)
      actual(5) += 1
    Case Is <= cumProbs(6)
      actual(6) += 1
    Case Else
      actual(7) += 1
  End Select
Next

Dim sumActual As Double = 0

Print "Letter", " Actual", "Expected"
Print "------", "--------", "--------"
For i As Integer = 0 To 7
  Print letters(i),
  Print Using "#.######"; actual(i)/n;
  sumActual += actual(i)/n
  Print , Using "#.######"; probs(i)
Next

Print , "--------", "--------"
Print , Using "#.######"; sumActual;
Print , Using "#.######"; 1.000000

Print
Print "Press any key to quit"
Sleep