Marginal Products and Average Products

The number of repairs produced by a computer repair shop depends on the number of workers as follows:

#of Workers                        #of Repairs

0                                     0
1                                     8
2                                     20
3                                     35
4                                     45
5                                     52
6                                     57
7                                     60

Assume that all inputs other than labor are fixed in the short run.

a)Add 2 additional columns to the table, and enter the marginal product and average product for each number of workers

b)Over what range of labor input are there increasing returns to labor? Diminishing returns to labor? Negative returns to labor?

c) Over what range of labor input is marginal product greater than average product? What is happening to average product as employment increases over this range?

d)Over what range of labor input is marginal product smaller than average product? What is happening to average product as employment increases over this range?

My Answer:

Workers    Repairs     MP       AP

0            0          -        -
1            8          8        8
2            20         12       10
3            35         15       11.6
4            45         10       11.2
5            52          7       10.4
6            57          5        9.5
7            60          3        8.5

Is my table correct?  I don't understand what the table is trying to say