I very much need some help with a postgres query.

I have 3 tables:

domains(
domain_id,
domain_name
)

stores(
store_id,
store_name,
domain_id
)

customer_prospects(
customer_id,
store_id,
salesperson_id
)

I need a query that will will give me the number of customer_prospects in each domain like"

"Select domain_name,count(customer_id) from ..."

How to write this really has me stumped. I can use multiple queries and foreach loops, but if it can be done in a query I would rather do it that way.

Please help!!