A note on research:
Suppose I was to pose the question: "What is the mass of the planet Jupiter, in Kg?"
Now, supposing that you were not an astrophysicist or space geologist, how would you go about getting a reliable answer to that question? Well, firstly, you might try Wikipedia. The Wikipedia entry for "Jupiter" says that its mass is 1.8986 x10
27Kg
http://en.wikipedia.org/wiki/Jupiter#cite_note-fact-4
Fair enough, you might say, but how might I corroborate that? You might then try the NASA site. That site (which is in fact the source of the Wikipedia data) also puts Jupiter's mass at 1.8986 x10
27Kg. You'd expect NASA to get Jupiter's mass correct on its own fact sheet, wouldn't you?
http://nssdc.gsfc.nasa.gov/planetary/factsheet/jupiterfact.html
So, how about a third source, just to corroborate further? Here's a Princeton University factsheet on Jupiter, which puts its mass at 317.83 times the mass of the Earth. And this tallies exactly with the mass ratio given in both Wikipedia and the NASA site.
http://www.princeton.edu/~willman/planetary_systems/Sol/Jupiter/
So, a little research can tell you with near certainty that the mass of Jupiter is 1.8986 x10
27Kg - or at least that this is the best estimate of its mass that anyone on Earth, alive or dead, has ever been able to make. And you've been able to find out this information without being a specialist in the field - you've merely used decent research skills (including good sourcing and multiple-source corroboration) and a minimum amount of scientific knowledge and basic reasoning. You haven't had to actually have the skills, knowledge or training to measure Jupiter's mass yourself*, but you've know where and how to look for reliable results from people who do have the skills, knowledge and training to make the complex measurements.
Now, suppose the question instead were this: "How long does a moderate-sized solid meal stay in the human stomach before it starts to pass through to the duodenum (what's the median time, and the probability curve either side of that median)?"
And suppose the supplementary question was this: "Given the information found in answer to the above question, what is the probability of a person's stomach still being full between 2.5 and 3.5 hours after starting the meal, compared with the probability of the stomach still being full over 4.5 hours after starting the meal?"
* Its mass is actually calculated by observing its gravitational pull on its moons, with knowledge of the distances between Jupiter and its moons and the orbit period of the moons. But you don't need to know that if the only question that needs answering is "What is Jupiter's mass?".