You have written ‘Y estimated price’ but the calculation would be based on Y’s actual share price.
On that basis, Y shareholders receive (3 x 9.24) + 1.33 = 29.05 for every 2 shares that they currently own, or 29.05/2 = $14.525 per share.
So a premium of (14.525 – 4.77)/4.77 = 204.5% (which makes it extremely unlikely that these would be the numbers in an actual exam question, because it is a ridiculously high premium 🙂 )