Part A The exponential model that describes the situation The formula is Y (x)=400 (1+0.02/4)^4x Y (x)=400 (1+0.005)^4x Y (x)=400 (1.005)^4x Where x is the number of years
Part B The value of the account after 5 years Y (5)=400×(1.005)^(4×5) Y (5)=441.96