Correction of errors — practice question

Nikita is a trader. Her trial balance totals at 30 June 2021 failed to agree. Debits were higher than credits by $2600$, so Nikita opened a suspense account. The errors discovered afterwards were as follows. 1 Insurance of $2500$ was recorded as $4500$ in the insurance account. The correct amount had already been entered in the cash book. 2 The $500$ total in the discount received column of the cash book was posted to the discount allowed account in the general ledger. 3 Credit sales of $1400$ to Kajal were entered correctly in the sales account, but Kajal’s account was debited with $1000$. 4 A cheque for $700$ received from Anisah was entered correctly in the cash book, but it was credited to Aisha’s account.