A debt of 8450 euro is amortized in 5 years and 6 months at 2% (annual) with quarterly amortization installments variable in geometric progression with first term 488.15 euro in compound convention. Knowing that the payment of the amortization installments is interupted after 6 months and for one year and 4 months, recover:

1. The ratio of the geometric progression
2. The effective rate of the contract for the debtor if the starting expense is 400 euro

Can please help me solve this exercise with trace?