The hottest careers for the '80s (with projected average salaries for 1990) says financial writer Thelma Kandel:

Data Processing: Programmers with three year's experience, $38,000; systems analysts with 5 year's experience, $45,000; data base managers with 9 year's experience, $58,000.

Engineering: Mechanical engineers with 4 year's experience, $40,000; electronics engineers with 3 year's experience, $42,000; energy engineers with 6 year's experience, $52,000.

Accounting and Finance: Cost accountants with 3 year's experience, $40,000; auditors with 5 year's experience, $42,000; financial vice presidents with at least 10 years $96,000.

Human Resources/Personnel: Technical recruiters with 4 year's experience, $37,500; personnel vice presidents with 11 years experience $82,000.

Marketing and Sales: Sales engineer with 6 year's experience, $41,000.

Secretary: At entry level, $18,000; after three years, $24,000.

Other fields with projected good growth rates: Banking -- officers and managers; Insurance -- agent, actuary, underwriter, broker, claims representative; Therapy -- occupational, physical, speech pathologist, audiologist, respiratory therapy worker; Science -- geologist, geophysicist, biochemist, life scientist; Health -- optometrist, dentist, podiatrist, veterinarian, registered nurse, pharmacist, dietician, psychologist; Economics -- economist, statistician.

Occupations with lower-than-average-growth rates: Anthropologist, credit manager, farmer, funeral director and embalmer, librarian, historian, furniture upholsterer, political scientist, sociologist, teacher (secondary school and college), telephone operator and installer.