The only mistake you made is the Z value for the 98% confidence level.
For 98% confidence, z value = 2.33
We will also use P= 0.5 as the population is not known.
The confidence interval (c) is known as 3% = 0.03
Now substitute:
SS= (z^2)*P (1-P)/ c^2
SS= [(2.33)^2 (.5)(1-0.5)]/(0.03)^2
= [(2.33)^2 (0.25)]/0.0009
= 1508. 027
==> SS = 1509 is the minimum sample size.