Q. Three years ago, the population of a certain species of bird was calculated at 20 birds per acre This year, a biologist recorded a total of 47 birds in an area equal to 3.25 acres. By about what
percentage has the bird population in the biologist's sample decreased over the last 3 years, to
the nearest tenth?
A. 14.7%
B. 27.7%
C. 38.3%
D. 42.6%
E. 72.3%