Case study: A Go Card account maintains a balance that may be spent on public transport. Users may request a statement that shows all transactions. The only transactions are to top up the account with some positive number of dollars, and to take a ride costing some dollars and cents. The goal for this exercise is to develop a class for a Go Card Account. The class will be tested by a program that simulates transactions, like this: Creating account. Input initial balance: 100 ? r 3.50 ? r 10.90 ? b Balance = $85.60