Question

louden county wildlife conservancy counts butterflies each year. data over the last three years regarding four types of butterflies are shown below. what inference can be made about the butterflies in louden county from the samples?
louden county butterfly count
2009 2010 2011
meadow fritillary 5 meadow fritillary 34 meadow fritillary 14
variegated fritillary 7 variegated fritillary 95 variegated fritillary 63
zebra swallowtail 33 zebra swallowtail 21 zebra swallowtail 10
eastern - tailed blue 242 eastern - tailed blue 168 eastern - tailed blue 170
all butterfly populations are steadily decreasing.
all butterfly populations were larger than usual in 2010.
the eastern - tailed blue butterfly is more common than the others.
the meadow fritillary is equally common as the variegated fritillary.

Explanation:

1. Check "All butterfly populations are steadily decreasing": Meadow Fritillary (5→34→14) and Variegated Fritillary (7→95→63) increased in 2010, so this is false.
2. Check "All butterfly populations were larger than usual in 2010": Zebra Swallowtail (33→21→10) and Eastern-Tailed Blue (242→168→170) decreased in 2010, so this is false.
3. Check "The Eastern-Tailed Blue butterfly is more common than the others": In every year (242, 168, 170), its count is far higher than the other three species, so this is true.
4. Check "The Meadow Fritillary is equally common as the Variegated Fritillary": Meadow Fritillary counts (5,34,14) are consistently lower than Variegated Fritillary (7,95,63), so this is false.

Answer:

C. The Eastern-Tailed Blue butterfly is more common than the others.