input: Write a python function to detect outliers in a dataset using the median absolute deviation method with a threshold of 3.
  assert detectOutliers([1, 2, 3, 4, 5, 6, 7, 8, 9, 10]) == []
  assert detectOutliers([1, 2, 3, 4, 100, 6, 7, 8, 9, 10]) == [100]
  assert detectOutliers([-10, 0, 1, 2, 3, 4, 5, 100, 6, 7, 8, 9, 10]) == [-10, 100]
output: def detectOutliers(data):
      import numpy as np
  
      median = np.median(data)
      deviation = np.abs(data - median)
      mad = np.median(deviation)
      threshold = 3
  
      outliers = []
      for i in range(len(data)):
          if deviation[i] / mad > threshold:
              outliers.append(data[i])
      
      return outliers