Gloria Dean Whipple, 51, a graphic artist and teacher, died Friday at George Washington University Hospital of injuries suffered in an attack on the Mall Sept. 17.

A Park Police spokesman said she apparently was mugged while walking across the Mall about 10:30 p.m. Her body was found near the Metro station at 12th and Jefferson streets.

She had been severely beaten and later underwent surgery at the hospital.The police spokesman said there were no witnesses to the attack and they have been unable to determine the motive.

Miss Whipple was walking to the Metro station after attending a graphic arts class at the Smithsonian when she was assaulted. She was a volunteer worker in the Residents Associates program there.

She had come to the Washington area in 1975 and had established a studio at the Pen Arts Headquarters in Washington. She taught editorial graphics at the adult education center of Northern Virginia Community College.

She also worked as a graphic artist for a business consultant firm and was a hostess at a Washington restaurant. In 1976, she was commissioned by Woodward & Lothrop to design a series of ethnic hand puppets used in a promotional campaign during Black History Month.

Miss Whipple was president of the Capital Branch of the National League of American Pen Women. She was treasurer of the Washington Area Writers Group. She wrote essays and public relations releases. She lived in Lorton, Va.

She was born in Chicago and grew up in Detroit, where she studied commercial art in high school and then graduated from the Meinzinger Arts School.

After her marriage to Allan Freiwald, a Detroit area building constractor, she lived in Grosse Pointe,Mich. She was active in art circles there and in Detroit. Her marriage ended in divorce.

She is survived by a daughter, Lynne Marie Freiwald, of Marquette, Mich., and a son, Deal Freiwalk, of Detroit.