ABSTRACT
Let cd(G) be the set of irreducible character degrees of a finite group G. Also, let cdP(G)⊆cd(G) and cdC(G)⊆cd(G) be the sets of all prime character degrees and all composite character degrees of G, respectively. We prove that for a solvable group G, if |cdC(G)|≥4, then . This extends the results of [Citation4], [Citation7], [Citation2] and [Citation3] where it has been proved that |cdP(G)|≤3 if |cdC(G)| = 0,1,or2, and |cdP(G)|≤4 if |cdC(G)| = 3, respectively.
2000 MATHEMATICS SUBJECT CLASSIFICATION:
Acknowledgment
The author is grateful to the referee for helpful comments and suggestions.