THERE SHALL BE a calculation BEYOND SIMPLE MULTIPLICATION on this table PLEASE EXPLAIN YOUR ANSWER

please fill out the table and give an explanation for your calculations, 

Item

Immediate predecessor

Duration (weeks)

No. of resources

Level of Effort (number of workers X duration of work)

Labor cost

Material cost

Total cost

A

4

2 designers @ $1,600/person/week

$1,000

B

A

2

2 programmers @ $1,200/person/week

$2,000

C

A

4

1 programmer @ $1,200/week/person

$2,000

D

B

6

1 testers @ $1,000/week/person

$5,000

E

C,B

3

2 testers @ $1,000/week/person

$ 2,000

F

D,E

3

2 integrators @ $1,800/week/person

$1,000

Total

$13,000