Your firm has an average receipt size of $125. A bank has approached you concerning a lockbox service that will decrease your total collection time by two days. You typically receive 5,800 checks per day. The daily interest rate is 0.017 percent. The bank charges a lockbox fee of $170 per day.

What would the net annual savings be if the service were adopted?

I have tried calculating savings as:

checks per day = 5800

average receipt size = 125

average receipts per day = 125 * 5800 = 725000

interest rate per day = 0.017%

interest per day = (725000* 0.017)/100 = 123.25

number of days reduced through service = 2

interest in 2 days = 123.25*2 = 246.5

savings per year = (246.5 - 170)*365= 27922.5

but 27922.5 does not seem to be a correct answer