Assume that the wavelengths of photosynthetically active radiations (PAR) are uniformly distributed at integer nanometers in the red spectrum from 675 to 700 m.

(a) What is the mean and variance of the wavelength distribu- tion for this radiation?

(b) If the wavelengths are uniformly distributed at integer nanometers from 75 to 100 nanometers, how does the mean and variance of the wavelength distribution com- pare to the previous part? Explain.