The average daily balance is the mean of the balance in an account at the end of each day in a month. the following table gives the dates and amounts of the transactions in elliott's account in june.

day of june transaction type transaction amount (in dollars)
1 starting balance 1223
10 deposit 615
15 withdrawal -63
22 withdrawal -120

there are 30 days in june.
what is the average daily balance of elliott's account for the month of june?