What is the physics equation for Power ?

If anyone who can me with this hw? i would really appreciate it

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

Wavelength of 125 meters is moving at a speed of 10 m/s. what is it's frequency?