Apparently all the computer records were lost during the transition. All I have are a few notes scratched on a piece of paper to guide me. We have three pay levels. Level 1 employees begin at $15,000. The notes say that in the third year the salary should rise to $19,000. Level 2 employees start at $30,000 and according to the notes their salary should rise to $36,000 in year 3. Finally, Level 3 employees start at $50,000 and the notes say that they should be making $58,000 by the end of year 3. The only other piece of information I have is that the growth of salary over time is supposed to follow a linear growth pattern - whatever that means. The notes also say that once a Level 1 employee has worked long enough to reach a salary of $30,000 he or she should either be promoted to Level 2 or fired. The same applies to Level 2 employees when they reach $50,000 in salary. Can you help me out

1) 2000/yr, 3000/yr, 4000/yr

2) y = ax + b

3) 7.5yrs, 6.7yrs

Explanation:

 We need first to know what exactly is the rate of increase for each level of employee over time. Also a mathematical model that will allow to input the number of years the employee has been working and give back their current salary. Finally, the years of working Level 1 employee should expect to be promoted to Level 2 and after how many years of working Level 2 employee be promoted to a Level 3.  

Solution:

Rate of increase( slope) = increase/number of years.

Level 1

(19000 - 15000)/2 =4000/2 = 2000/year

Level 2

(36000 - 30000)/2 = 6000/2 = 3000/year

Level 3

(58000 - 50000)/2 = 8000/2 =4000/year

Mathematical model: y = ax + b

Where y = current salary

X = number of years

a = slope

b = starting salary

Number of years of promotion:

Level 1

30000 = 2000x + 15000

X = 7.5yrs

Level 2

50000 = 3000X + 30000

X = 6.7yrs

answer; according to the ( irs );