â The presence of marijuana is detected by a drug test through the presence of the active chemical THC or Tetrahydrocannabinol. Technically, what is detected is known as THC-COOH (11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid).
1 Average Riding Instructor Salary: Independent riding instructors typically charge an hourly rate for services but on average earn about $35,000 to $39,000 per year.
Training, experience and certification could all affect salaries. The published average salary for a personal trainer varies according to the source. O*NET Online reports fitness trainers and aerobics instructors earned a median salary of $33,020 in 2013. The U.S. Bureau of Labor Statistics reports an average annual salary of $37,790 for 2013.