1. The problem involves verifying the correctness of a series of electricity payments and charges recorded as credits (+) and debits (-) with running balances. 2. The key formula to check is: $$\text{New Balance} = \text{Previous Balance} + \text{Transaction Amount}$$ 3. To verify correctness, start from the earliest balance and sequentially add each transaction amount to the previous balance. 4. If the resulting balance matches the recorded balance after each transaction, the calculation is correct. 5. If there is any mismatch, the calculation is incorrect and the correct balance should be recalculated by summing all transactions from the initial balance. 6. This process requires careful addition and subtraction of each transaction amount in chronological order. 7. Without the initial balance explicitly stated, assume the earliest balance given (e.g., £5,868.38 on 1 Oct 2019) as the starting point. 8. Then, add or subtract each transaction amount in order, checking if the resulting balance matches the recorded balance. 9. If discrepancies are found, the correct balance at any point is the sum of the initial balance plus all transactions up to that point. 10. This method ensures accurate tracking of account balance over time. Final answer: To verify if the calculation is correct, use the formula $$\text{New Balance} = \text{Previous Balance} + \text{Transaction Amount}$$ and check each step sequentially. If any balance does not match, recalculate by summing all transactions from the initial balance to that point.