Line 1: Line 1:
 
<math>\theta </math> is uniform [0,1]
 
<math>\theta </math> is uniform [0,1]
 +
 +
E[ <math>\theta^2 </math> ] = <math>\int\limits_{0}^{1} \theta^2 d\theta </math>
 +
= 1/3
  
 
supp. <math>\theta^{hat}</math> = 1/3
 
supp. <math>\theta^{hat}</math> = 1/3
  
MSE = E[ (<math>\theta</math> - 1/3)^2 ] = E[ <math>\theta</math>^2 - 2*(1/3)*<math>\theta</math> + (1/3)^2 ]
+
MSE = E[ (<math>\theta</math> - 1/3)^2 ] = E[ <math>\theta^2</math> - 2*(1/3)*<math>\theta</math> + (1/3)^2 ]
 
= 1/3 - 2(1/3)(1/2) + (1/3)^2 = (1/3)^2 = 1/9
 
= 1/3 - 2(1/3)(1/2) + (1/3)^2 = (1/3)^2 = 1/9
  
 
supp. instead <math>\theta^{hat}</math> = 1/2
 
supp. instead <math>\theta^{hat}</math> = 1/2
  
MSE = E[ (<math>\theta</math> - 1/2)^2 ] = E[ <math>\theta</math>^2 - 2*(1/3)*<math>\theta</math> + (1/4) ] = 1/3 - 1/2 + 1/4 = 1/12
+
MSE = E[ (<math>\theta</math> - 1/2)^2 ] = E[ <math>\theta^2</math> - 2*(1/3)*<math>\theta</math> + (1/4) ] = 1/3 - 1/2 + 1/4 = 1/12

Revision as of 17:15, 7 December 2008

$ \theta $ is uniform [0,1]

E[ $ \theta^2 $ ] = $ \int\limits_{0}^{1} \theta^2 d\theta $ = 1/3

supp. $ \theta^{hat} $ = 1/3

MSE = E[ ($ \theta $ - 1/3)^2 ] = E[ $ \theta^2 $ - 2*(1/3)*$ \theta $ + (1/3)^2 ] = 1/3 - 2(1/3)(1/2) + (1/3)^2 = (1/3)^2 = 1/9

supp. instead $ \theta^{hat} $ = 1/2

MSE = E[ ($ \theta $ - 1/2)^2 ] = E[ $ \theta^2 $ - 2*(1/3)*$ \theta $ + (1/4) ] = 1/3 - 1/2 + 1/4 = 1/12

Alumni Liaison

Basic linear algebra uncovers and clarifies very important geometry and algebra.

Dr. Paul Garrett