6
In this case there is also a good agreement between the proposed line spectrum and the actual spektrum. In specific cases it is obviously possible to support or discard a proposed structure based on a comparison between the line spectrum based on that hypothetical structure and the actual, experimental spectrum of the compound.
You have been able to solve the first two problems. This demonstrated that you have at least a tenuous grasp of the concepts involved in the spectra of simple compounds. Take heart - great carreers have been launched with less - and jump ahead to apply your newly acquired knowlegde.