Two energy resources that have another source of their energy

What happens to light waves from a star as the star moves away from earth?

Most short-period comets do not have randomly oriented orbits because

Asynthetic fiber used in manufacturing carpet has tensile strength that is normally distributed with mean 75.5 psi and standard deviation 3.5 psi. how is the standard deviation of the sample mean changed when the sample size is increased from n equals 8 to n equals 47