Pharmaceutical companies prefers experimental studies to conducting surveys and observational studies because companies can manipulate or suggest methods easily to have good outcomes and they are able to directly observe the results. Experimental studies is a type of study in which a procedure and method is intentionally introduced.
Answer:
$21
Step-by-step explanation:
Add what she spent to what she has left.
Vertical line has no slope. so only look at the x value. x=-4.
