N ( ,  2 ) N ( -10 10 ,   0.1 10 )
  N ( ,  2 ) N ( -10 10 ,   0.1 10 )
  N ( ,  2 ) N ( -10 10 ,   0.1 10 )
  

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<Figure 5.4.7> Three Normal distribution N(-2,0.25), N(0,1), N(2,4)