Which option below best describes the difference between an experiment and an observational study?

a. The values in an experiment are chosen at random, but not in an observational study.
b. The values in an observational study are chosen at random, but not in an experiment.
c. The groups in an experiment are chosen at random, but not in an observational study.
d. The groups in an observational are chosen at random, but not in an experiment.

Desmond wants to sell his car that he paid $8,000 for 2 years ago. the car depreciated, or decreased in value, at a constant rate each month over a 2-year period. if x represents the monthly depreciation amount, which expression shows how much desmond can sell his car for today? 8,000 + 24x 8,000 - 24x 8,000 + 2x 8,000 - 2xdesmond wants to sell his car that he paid $8,000 for 2 years ago. the car depreciated, or decreased in value, at a constant rate each month over a 2-year period. if x represents the monthly depreciation amount, which expression shows how much desmond can sell his car for today? 8,000 + 24x 8,000 - 24x 8,000 + 2x 8,000 - 2x