Rank the following compounds in order of increasing basicity (weakest → strongest)

Alkyl amines are more basic than aryl amines or amides due to delocalization of lone pair of N in later case or in case of amides. Electron withdrawing group like NO2 also result in decreased electron density over N-atom of amine group and hence, makes the aniline less basic.Thus, the order of basicity isIV < III < I < II