To determine the squirrel population in a city park, researchers tagged 90 squirrels. Later, they counted 630 squirrels, 42 of which had tags. Based on this data, what is the estimated total number of squirrels in the park, rounded to the nearest whole number?
If they had rounded up the whole population, they'd have found all 90 tagged squirrels. So, if the population is x, then
630 = 42/90 x
x = 1350