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.
According to Payscale.com, the average starting salary in 2016 for mechanical engineers is $62,527 and the mean annual salary for all mechanical engineers is $88,190 according to the Bureau of Labor Statistics (BLS) in 2015. Civil Engineering.