Re: Hidden information question

Reef Fish wrote:
Bjoern wrote:
Reef Fish wrote:
Jerry Dallal wrote:

Schizoid Man wrote:

Several coworkers would like to know their average salary. How can they
calculate it, without disclosing their own salaries?

PS: assumptions used
a) everyone is honestly interested in learning the true average salary
b) everyone is in theory also interested in everyone else's exact salary

That is neither necessary nor tenable.

In fact, I'll disagree with Bjoern here. I did not interpret the coworkers as duplicitous.

I read the problem as an honest desire to obtain the mean without revealing individual salaries. While it is an inference, it is not necessarily an unreasonable one that they would work cooperatively toward the common goal. In that case, the single random number with a way of collecting a running total so that each individual knows only one value prior to adding in his/her own salary will suffice. If there is
cheating, then the scheme falls apart, but it's still a cute problem, in that the solution is not transparent to most people even when the honesty (no sharing, adding in actual salary) of the participants is explicit.
.