Issue of shares

A company offered 6000 shares at $90 per share. And received 9200 applications. The company rejected and refund 200 application and allotted the remaining on pro-rata basis Application cost = 10 Allotment = 20 First call = 30 Final call - 30 Journal entry: 1. Dr Bank 92000, Cr Application 92000 2. Dr Application 2000, Cr Bank 2000 3. Dr Application 90000, Cr Original share 60000, Cr Allotment 30000 4. Dr Bank 90000, Cr Allotment 90000 5. Dr Allotment 120000, Cr Original shares 120000 6. Dr Bank 180000, Cr first call 180000 7. Dr first call 180000, Original shares 180000 8. Dr Bank 180000, Cr first call 180000 9. Dr first call 180000, Original shares 180000 Every account is closed except, Ordinary share 540,000 and Bank 540,000 This is a shortened question and answer i found on internet, so is the journal entry correct? If so, i dont quite understand "Number 4", where did the Dr Bank 90000, Cr Allotment 90000 come from? Also, i dont quite understand pro-rata basis, like how do we use it? What does it do?