This can be calculated by applying Wein displacement law which is stated as follows;
Maximum wavelength (m)*Temperature (K) = 2.90 *10^-3 m.K
Therefore, substituting for the values given;
Wavelength = (2.90*10^-3)/T = (2.90*10^-3)/4400 = 6.59*10^-7 m ≈ 659 nm
