정의 된 방정식이 올바르게 변환되지 않음

입력 한 영국식 측정 값을 미터법으로 변환하려고하는데 변환이 올바르지 않고 그 이유를 잘 모르겠습니다. 예를 들어, 50 파운드의 총 중량 영국식 단위 입력을 합하면 출력은 17.72kg이됩니다. 조언, 비평가 또는 코드 변경을 환영합니다. 이것은 내 코드입니다.

# Convert the total weight from Imperial, to Metric units
def convertWeight(totalWeight):
  return (totalWeight * 0.45359237)

# Calculate the cost of transport, by multiplying certain weight conditions by their respective cost per kilograms
def getRate(totalWeight):
  if totalWeight <= 2:
      rate = totalWeight * 1.10
  elif totalWeight > 2 and totalWeight <= 6:
      rate = totalWeight * 2.20
  elif totalWeight > 6 and totalWeight <= 10:
      rate = totalWeight * 3.70
  elif totalWeight > 10:
      rate = totalWeight * 4.20
  return rate

# Get the number of boxes
numBoxes = int(input('Please enter the number of boxes: '))
# Get the unit of measurement
unit = input('Please enter the unit of measurement, Imperial or Metric (as I or M): ')
# If the inputted unit of measurement does not equal one of these conditions, ask again for the unit of measurement, until one of these characters are inputted.
while unit not in ['I','M','i','m']:
   unit = input('Please enter the unit of measurement again, Imperial or Metric (as I or M): ')

totalWeight = 0
# For each box, get their respective weight
for x in range(numBoxes):
   weight = float(input('Please enter the weight of the boxes: '))
# Sum up the total weight by adding the inputted weights
   totalWeight = totalWeight + weight
# Does not work, check Parlas answers ; If the inputted unit is Imperial, convert it to Metric
   if unit in ['I', 'i']:
       totalWeight = convertWeight(totalWeight)
   else:
      totalWeight = totalWeight

# Calculate the transport cost, by calling the rate function
transportCost = getRate(totalWeight)
# Output the number of boxes, the total weight, and the transport cost to the user
print('The number of boxes is {0}, the total weight is {1:.2f} kilograms, and the transport cost is ${2:,.2f}.' .format(numBoxes, totalWeight, transportCost))