Aresearcher approximated the number of cactus plants in a region of desert that is roughly square shaped with a side length of 175 kilometers. as part of the process, he counted the number of cactus plants in a small part of the region and determined that the density of cactus plant was about 214 plants per square kilometer. he assumed the density of cactus plants was the same throughout the region. which expression would the researcher have most likely used when making his approximation for the number of cactus plants in the square shaped region (3 × 10^5) (2 × 10^2) 3 × 10^4 / 2 x 10^2 (3 × 10^4) (2 × 10^2) 3 × 10^5 / 2 × 10^2