The Violent Crime Rate (Number of Violent Crimes Per 100,000

Essay

The violent crime rate (number of violent crimes per 100,000 residents)is investigated for nine Canadian cities for the years 1990 and 2000 to see if there has been a change. $$\begin{array} { c | c | c | c | c | c | c | c | c | c } \text { City } & \text { A } & \text { B } & \text { C } & \text { D } & \text { E } & \text { F } & \text { G } & \text { H } & \text { I } \\\hline \begin{array} { c } \text { Violent crime rate } \\\text { in 2000 } \\\text { Violent crime rate } \\\text { in 1990 }\end{array} & 325 & 250 & 199 & 785 & 645 & 259 & 855 & 679 & 301 \\\text { in } &379& 355 & 175 & 925 & 750 & 405 & 1005 & 902 & 455\end{array}$$ Is there evidence that the violent crime rate has decreased? Suppose you had mistakenly treated these data as two independent samples instead of matched pairs.What would the significance test have found? Explain why the results are so different.