Projected Salary and Hours Calculation

Hello,

I have a question regarding on  how the system calculates the projected salary and projected hours worked in the position activity application

I am giving the following example:

I created a position with:

Position Budget Amount: 20.000

Budgeted FTE: 2

Budgeted Hours: 5760 

Headcount: 2

and Effective From Date: 1/1/2015         

I hired an employee on 1/7/2015 in the above position with annual salary $ 12,000.00

I am going to see the position activity and the projected salary is 6,049.32 and  projected hours worked 1,451.84 hrs.

I expected to be $6,000.00 and 1,440.00 hours worked as the employee was hired in the middle of the year

So, how the system calculates the above amounts?