A question in the proof of Rao-Blackwell theorem

1.3k Views Asked by At

This could be a naive question but I am just puzzled. I am learning the following proof of Rao-Blackwell theorem but get puzzled by the equation in the red box. Why the two expectations can be reduced to one expectation? Thank you.

enter image description here

1

There are 1 best solutions below

3
On BEST ANSWER

This is an application of the law of total expectation.