Compared to the critical density of matter, about how much matter and dark energy is there?

Question

Quizplus · Accepted Answer

Recent observations of the cosmic microwave background radiation and the large-scale structure of the universe suggest that the total energy density of the universe is very close to the critical density, where the geometry of the universe is flat. However, only about 30% of this density can be attributed to matter, including dark matter. The remaining 70% is attributed to dark energy, which is causing the accelerated expansion of the universe. Thus, the best choice is B.

Compared to the Critical Density of Matter, About How Much