Tidewater City Bank has four branches with the following inputs and outputs:

input 1 = teller hours (100s)
input 2 = space (100s ft.2)
input 3 = expenses (+1,000s)

output 1 = deposits, withdrawals, and checks processed (1,000s)
output 2 = loan applications
output 3 = new accounts (100s)

The monthly output and input values for each bank are as follows:

                                

Using data envelopment analysis (DEA), determine which banks, if any, are inefficient.