Explain why CH3 group is ortho,para orienting,while-NO2 group is meta orienting?

When toluene undergoes electrophilic aromatic substitution the products are primarily the ortho and para isomers; usually only a small amount of the meta isomer is produced. In order to explain this observation there are two effects to consider, inductive and resonance effects.Inductively the methyl group releases electron density into the benzene ring. This is because the methyl group, being sp3 hybridized, is less electronegative than the sp2 hybridized aromatic carbon. The carbon with more s-character is more electronegative, electron density likes to flow from low to high s-character orbitals since the more s-character in an orbital, the lower its energy. If inductive arguments were most important we would expect the ortho isomer to predominate followed by the meta and para isomers in that order. This is not observed, the meta isomer is only a minor isomer.