Someone explain margin rates for online brokers?

[Two-Niner]

I'm a newbie to onlinve investing and had a question on margin rates. I see for example Scottrade has a 10% margin rate. Would using this margin make profits pretty hard to come by, IE would you have to make more than a 10% return on the stocks you buy on that margin? Say if you use $1,000 of margin to buy a stock then sell it a few weeks later. How much would you have to pay the online broker for the margin loan? Thanks for helping with the dumb question!

 

[BASEHEAD]

If you opened an acct. @ scottrade for example deposited 2000 in your margin account-@ 10% margin rate would equal 2400 dollars worth of purchasing power.You'd be responsible for repayment of the 400 (plus interest).