The thing is that it gives you questions to ask. I am sure NYC population is a web search away. Or tuning frequency recommendations for pianos. Or how long does tuning a piano really take? Some are certainly harder (how frequent are piano-households?), but maybe someone already looked into it.
It shows that one can break a problem down into more manageable pieces. Being more manageable means you can get a better estimate by delving deeper.
The question is not about finding the right answer, but about employing the right methodology.
And if you've got next-in-the-chain taking estimates as hard boundaries or facts, you need to be explicit they are not, and hopefully teach them to be a bit more suspicious of everything.
Even then, it's ok if someone else takes your ballpark and runs with, as long as you are willing to take responsibility. If you are higher in job title, be explicit this is what you are asking them to do, and that you will take the responsibility! Invite them to improve upon it as they learn more, though!
It shows that one can break a problem down into more manageable pieces. Being more manageable means you can get a better estimate by delving deeper.
The question is not about finding the right answer, but about employing the right methodology.
And if you've got next-in-the-chain taking estimates as hard boundaries or facts, you need to be explicit they are not, and hopefully teach them to be a bit more suspicious of everything.
Even then, it's ok if someone else takes your ballpark and runs with, as long as you are willing to take responsibility. If you are higher in job title, be explicit this is what you are asking them to do, and that you will take the responsibility! Invite them to improve upon it as they learn more, though!