If c dollars are deposited in an account paying annual percent interest,

approximate the amount in the account after x years if c=$250, r=2.0%, and x=19 years..

You need to define whether the interest is simple or compound.
Compound interest: A = P*(1+i)^n
simple interest: A = P*(1+ni)
where A is the amount you end up with, P is the principal you start with, i is the interest rate per period, and n is the number of periods. (forgive the grammar).

So...
Simple interest: A = 250*(1+0.02*19) = 345
Compound interest A = 250*(1+0.02)^19 = 364.20

250*2%=5(19)=95$+250$=345$

amount of interest you will receive in 19 years:
250 * .02 * 19 = 95
250+95 = 345