Interpretation of an NMR spectrum involves correlating the number, position, multiplicity, and integration of signals with the chemically different hydrogen or carbon environments present in an organic compound. In proton NMR (^1H NMR), the chemical shift (δ) is expressed in parts per million (ppm) relative to tetramethylsilane (TMS), which is assigned δ 0.00 ppm. The position of a signal depends mainly on the electronic environment of the nucleus, particularly the presence of electronegative atoms, π-bonds, aromatic rings, carbonyl groups and hydrogen bonding. The splitting pattern gives information about neighbouring nonequivalent protons, while integration gives the relative number of protons responsible for each signal. The spectra of the compounds referred to in the question are not included here, so exact assignment of individual signals to particular compounds cannot be made without seeing the structures or spectra. However, the expected δ values and their interpretation can be established from the characteristic proton environments normally encountered in organic compounds. Simple saturated alkyl protons generally appear in the region δ 0.8–1.5 ppm. Thus, a terminal methyl group, R–CH3, usually gives a signal around δ 0.8–1.0 ppm, whereas a methylene group, R–CH2–R, commonly appears around δ 1.2–1.5 ppm. A methine proton, R3CH, generally occurs near δ 1.4–2.0 ppm. The exact position changes according to the substituents attached to the carbon. For example, the methyl protons of ethane occur close to δ 0.9 ppm, while the methylene protons of propane occur around δ 1.3 ppm. Their multiplicities are explained by the n + 1 rule. A CH3 group adjacent to CH2 therefore normally appears as a triplet, while the CH2 group adjacent to CH3 appears as a quartet. Protons situated next to an electronegative atom are shifted downfield because the electronegative atom withdraws electron density and deshields the proton. For example, protons in R–CH2–O– groups generally occur around δ 3.3–4.0 ppm. The CH3 protons of methanol may appear around δ 3.3–3.5 ppm, whereas the O–CH2 protons of an