Many bank accounts never go below zero. But some banks will allow a negative balance, at least for a short time, called an overdraft. It means someone has taken out, or 'drafted', more money than was in the account to begin with. Joshua's account went into overdraft. To get back to a positive balance, he deposited money at a steady rate of $22.5 per week. After 4 weeks, he had $69.21 in the account. What was the balance when the account went into overdraft?