How do you assign weight to the activities

Hi, i need to specify the weight (incidence, etc) of the activity. Using the resources....a mean work hours...

if i have:

Proyect Name            10 working hours (summarize)       % of working hours of total

- Act 1                      2 working hours                             20%

- Act 2                      2 wh                                            20%

- Act 3                      2 wh                                            20%

- Act 4                      4 wh                                            40%

how do you show this percent? .... do you have to create?? how do you create?? .... (sorry my english), hope you can helpme

Bye!