Consider a Situation in Which Chris Predicts That an Impending

Multiple Choice

Consider a situation in which Chris predicts that an impending drainage connection will alter the number of fish in a set of six small lakes. She uses a large net (a seine) and counts the number of fish and obtains the values shown. What is the difference in the mean population density values?
?
Number of fish caught in six seines before and after drainage connection.

$\begin{array}{lll}\underline {\text {Vial } }&\underline {\text { Before } }&\underline {\text { After } }\\1 & 24 & 20 \\2 & 35 & 31 \\3 & 64 & 59 \\4 & 51 & 52 \\5 & 25 & 22 \\6 & 48 & 39\end{array}$

A) -1.0
B) -2.0
C) -3.0
D) -4.0