A Survey Was Designed to Study How Brook Trout Populations

Multiple Choice

A survey was designed to study how brook trout populations respond to various levels of urbanization. Urbanization had three levels: low, medium, and high impact. Historical habitats for brook trout were observed, with 200 habitats randomly selected within each level of urbanization, for a total of 600 habitats. Researchers marked each population as extirpated or present. The data are given in the following two-way table.
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$$\begin{array} { | l | l | l | l | } \hline & \text { Extirpated } & \text { Present } & \text { Total } \\\hline \text { Low impact } & 25 & 175 & 200 \\\hline \text { Medium impact } & 80 & 120 & 200 \\\hline \text { High impact } & 195 & 5 & 200 \\\hline\end{array}$$ What percent of all historical brook trout populations were found to be extirpated in the sample?

A) 12.5%
B) 40.0%
C) 50.0%
D) 97.5%