This table represents a linear function. What is the rate of change?

What is the best way to answer questions with a x expression in the question. for example 3x + 10x=?

Question 1 of 10 2 points different groups of 50 graduates of an engineering school were asked the starting annual salary for their first engineering job after graduation, and the sampling variability was low. if the average salary of one of the groups was $65,000, which of these is least likely to be the average salary of another of the groups? o a. $64,000 o b. $65,000 o c. $67,000 o d. $54,000

Math i have no idea how to do a and b