Dps: Why do you think that?
- South Dakota Population = 865,454
- US JW-to-Population Ratio = 263
The article says 330, therefore most likely they've missed the last '0'.
- Therefore JWs in South Dakota is expected to be around = 3,290
Additionally it appears that the figure of 3,330 was actually obtained in the first place by doing the above calculation.
Two people have identified themselves as "serving where the need was great" in South Dakota.
Which indicates that the area had a lower population ratio of JWs than other places in the States. If the journalist did, indeed, just do a calculation based on numbers that extrapolates the SD JW population from the US JW population ratios, then it is likely too high.