The following table presents the number of police officers (per 100,000 citizens) and the annual murder rate (per 100,000 citizens) for a sample of cities. $$\begin{array} { c c }
\hline \text { Police Officers (per 100,000) } & \text { Murders (per } 100,000 \text { per yr) } \
\hline 1109 & 46 \
1238 & 44 \
1235 & 38 \
1298 & 40 \
1077 & 49 \
1076 & 42 \
\hline
\end{array}$$ Compute the correlation coefficient between the per capita number of police officers and the per capita
Murder rate.
A) -0.726
B) -0.666
C) 0.444
D) -0.444

Question

The following table presents the number of police officers (per 100,000 citizens) and the annual murder rate (per 100,000 citizens) for a sample of cities. $$\begin{array} { c c } 
\hline \text { Police Officers (per 100,000) } & \text { Murders (per } 100,000 \text { per yr) } \
\hline 1109 & 46 \
1238 & 44 \
1235 & 38 \
1298 & 40 \
1077 & 49 \
1076 & 42 \
\hline
\end{array}$$ Compute the correlation coefficient between the per capita number of police officers and the per capita
Murder rate.
A) -0.726
B) -0.666
C) 0.444
D) -0.444

Quizplus · Accepted Answer

Using a calculator or statistical software, we find that the correlation coefficient between the number of police officers and the murder rate is -0.666, which indicates a strong (negative) correlation. Option B is the closest to this value.

The Following Table Presents the Number of Police Officers (Per