Environmental vulnerability of amphibians. Many species of amphibians are declining due to dramatic changes in the environment. The environmental vulnerability of amphibian species native to Mexico was examined in Amphibian &

Reptile Conservation (Aug. 2013). The researchers quantified this decline using a modified Environmental Vulnerability Score (EVS) algorithm. Scores ranged from 3 to 20 points, with higher scores indicating a greater level of environmental vulnerability. EVS scores for 382 snake species were determined and are summarized in the table below. Let x represent the EVS score for a randomly selected snake species in Mexico.

EVS Score 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Total Number of Snake Species 1 1 7 10 9 19 17 30 25 31 46 52 50 44 24 9 7 0 382 Source: Wilson, L. D., et al. “A conservation reassessment of the amphibians of Mexico based on the EVS measure.” Amphibian & Reptile Conservation, Vol. 7, No. 1, Aug. 2013 (Table 4).

a. Specify the probability distribution for EVS score x.

b. EVS scores greater than 14 are indicative of species that are endangered due to high environmental vulnerability.

Find P1x 7 142.