NORM.S.INV function
    NORM.S.INV(Probability) NORM.S.INV(Probability)
  
  Probability
        Number or { Number }
      
      A probability associated with the distribution.
Returns
        Number or { Number }
      
      The inverse of the cumulative NORM.S.DIST function.
Returns the inverse of the cumulative NORM.S.DIST function.
Example
      NORM.S.INV(0.7)NORM.S.INV(0,7)
      
    
    Returns roughly 0.5.