I am an average excel user and cannot figure out if this function is possible.

I have a data list with company name, contact name, address, city, state,
zip, and sales rep. It has over 10,000 names. I need to find out how many
companies in each state then subtotal it by each city. I also want the city
name to appear with the total without having to type it in for each one.

This would be used for the sales person to know how many companies are in a
particular city.

Thank you.