The formula for CI to be calculated for principal P and at rate R is P((1+(R/100))^T), where T is the time period.

Let the principal be Rs. P and the rate of interest be R % per annum.

Given, P(1+R/100) - P = 2592 and P(1+R/100)^3 - P(1+R/100)^2 = 3528.

We get, PR = 259200 and PR(1+R/100)(1+R/100) = 352800.

Solving the above two equations, we get

R = 50/3 and P = 15552.

CI for 4th year can be calculated by P(1+R/100)(1+R/100)(1+R/100)(R/100).

Solving which we get, CI for 4th Year = Rs. 4116.