there is a question about math,thank you for your help!

The cumulative distribution function, F(X) , of the amounts of money, X dollars, loaned to customers in a bank is given below. fraction of customers 1 0.8 0.6 0.4- 0.2 0 0.000 100.000 150.000 200.000 250.000 300,000 350.000 400.000 450.000 500.000 S Roughly what fraction of customers have loans between $250,000 and $300,000