1. Give two reasons why it is important to collect meta-data.
a)
b) 

2. Consider a data set where we have sales data for multiple products
(top Aphids, Bats, Cats, and Dogs) by city, state and country, by
month, quarter and year.  Give an example of each of the following
operations. In each case, state what the result of the operation is
(e.g. " a table diplaying sales for product A by month").  For (c) and
(d), note what table you have before the operation and what you have
afterwards.

(a) slice, 
(b) dice, 
(c) roll-up, 
(d) drill down

3. In the text, Exercise 3.4