You have to reason with proportions here while also using the given table. Our table tells us New York's density for various years. The question gives us the density for 1830. The density of the state is the ratio of the population to the amount of land; if the amount of land stays constant, then the density will increase at the same rate as the population. Now we could work with any of the density figures given in the chart, but it's probably easiest to work with 1920s: New York's population in 1920 was approximately 10 million people, a very nice round number to work with. In addition, the 1830 density was 44 people per square mile: very close to one-fifth of the 1920 density, 217.9 people per square mile. That means the 1830 population must have been about one-fifth of the 1920 population. The 1920 population was about 10 million, so the 1830 population must have been approximately $$\frac{1}{5}$$ of 10 million or 2 million people.