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.