Two person are interested in buying a house at auction. They have each collected surveys of the value of the land - person 1 knows s1 and person 2 knows s2. Neither person knows the value of the other's survey: they only know that it is uniformly distributed on [0,10]. Both person know that V, the true value of the land, is equal to the average of the two surveys: V=s1+s2/2.

1. person 1 learns that s1=7. What is person 1's current expectation of V?