I have an excel-worksheet as follows

Date Weekday kg (kilogram) packages
04-09-01 Wednesday 15000 26
04-09-01 Wednesday 14000 24
04-09-02 Thursday 19040 81
04-09-02 Thursday 17002 83
04-09-02 Thursday 11576 62
04-09-02 Thursday 13408 40
04-09-02 Thursday 16054 40
:
:
:

The data describes transports from a warehouse where each row is a
transport by lorry. The data is from 12 months and is 6500 rows. I need
answers to questions similar to:

How many lorries departs from the warehouse (on average) per day, per
week, per month
How many lorries departs from the warehouse on Mondays (on average)
How many packages contains each lorry (on average) on Thursdays
How many kilograms contains each lorry (on average) on Mondays

I think the basic problem is how to summarise the different info for
each day

I have looked at articles on Microsoft Knowledge Base but it doesn't
help me very much. Or maybe I've just read the wrong article.

I would be very grateful for some help in this matter.