Bank granted a $3$ year credit. Each fixed installment in amount of PLN $90,000$ is paid at the begining of each $4$M$.$ The bank offers also equilibrium rate under quarterly capitalization equaling $12\%$ p$.$a$.$ Find the rate applicable to the credit offered by the bank and calculate the principal amount of this credit.

$695450$

$1080000$

$923417$

$810000$

$695947$