A scientific theory is a well-substantiated explanation of some aspect of the natural world that is acquired through the scientific method and repeatedly tested and confirmed, preferably using a written, pre-defined, protocol of observations and experiments.
Process Engineer Salary. A Process Engineer earns an average salary of $70,876 per year. A skill in Simulation is associated with high pay for this job. Most people move on to other jobs if they have more than 20 years' experience in this field. $52,970 - $97,247.
Entry-level mechanical engineers holding bachelor's degrees earned average annual starting salaries of $61,300, according to the National Association of Colleges and Employers' Spring 2012 Salary Survey.