A diffraction grating is 1.68 cm wide and contains 2400 lines. when used with light of a certain wavelength, a third-order maximum is formed at an angle of 17.9°. what is the wavelength (in nm)?

The number of passengers who arrive at the platform of a subway station for the 10 am train is a random variable with a mean of 120 and a variance of 16. find the lower bound of the probability that there will be between 100 and 140 passengers (round off to second decimal place).