Humans aren't the only animals that get cancer, other organisms get tumors as well and their risk may be influenced by environmental factors. An ecologist decides to study whether pollution in lakes causes cancer so he collects 100 fish from each of two lakes, one known to be polluted and the other known to be pristine. He then dissects them and determines if they have tumors in their tissues or not. His data is shown below.

$\begin{array}{|l|l|l|}
\hline & \text { Polluted } & \text { Pristine } \
\hline \text { Tumors present } & 26 & 15 \
\hline \text { No tumors } & 74 & 85 \
\hline
\end{array}$
-What is the odds ratio for tumors for fish in the polluted lake compared to the pristine lake?

Question

Humans aren't the only animals that get cancer, other organisms get tumors as well and their risk may be influenced by environmental factors. An ecologist decides to study whether pollution in lakes causes cancer so he collects 100 fish from each of two lakes, one known to be polluted and the other known to be pristine. He then dissects them and determines if they have tumors in their tissues or not. His data is shown below.
​
 $\begin{array}{|l|l|l|}
\hline & \text { Polluted } & \text { Pristine } \
\hline \text { Tumors present } & 26 & 15 \
\hline \text { No tumors } & 74 & 85 \
\hline
\end{array}$
-What is the odds ratio for tumors for fish in the polluted lake compared to the pristine lake?

Quizplus · Accepted Answer

The odds ratio is calculated as (26/74) / (15/85) = 1.99.

Humans Aren't the Only Animals That Get Cancer, Other Organisms