Loan Amount: $398,483
Interest: 3.12
Length in months: 10
Payment 40,420.35


Payment schedule I came up with:
Payment 1:
  Beginning Balance: $398,483
  Interest: $1,036.06
  Principal: $39.384.29
  Ending Balance: $359,098.71

Payment 2:
  Beginning Balance: $359,098.71
  Interest: $933.66
  Principal: $39,486.69
  Ending Balance: $319,612.02

Payment 3:
  Beginning Balance: $319,612.02
  Interest: $830.99
  Principal: $39,589.36
  Ending Balance: $280,022.66

Payment 4: $280,022.66
  Beginning Balance:
  Interest: $728.06
  Principal: $39,692.29
  Ending Balance: $240,330.37

Payment 5: $240,330.37
  Beginning Balance:
  Interest: $624.86
  Principal: $39,795.49
  Ending Balance: $200,534.88

Payment 6:
  Beginning Balance: $200,534.88
  Interest: $521.39
  Principal: $39,898.96
  Ending Balance: $160,635.92

Payment 7:
  Beginning Balance: $160,635.92
  Interest: $417.65
  Principal: $40,002.70
  Ending Balance: $120,633.21

Payment 8:
  Beginning Balance: $120,633.21
  Interest: $313.65
  Principal: $40,106.70
  Ending Balance: $80,526.52

Payment 9:
  Beginning Balance: $80,526.52
  Interest: $209.37
  Principal: $40,210.98
  Ending Balance: $40,315.54

Payment 10:
  Beginning Balance: $40,315.54
  Interest: $104.82
  Principal: $40,315.53
  Ending Balance: $0.01

$319,612.02.

$319,612.01

$359,098.71 - $39,486.69 = $319,612.01