In an Effort to Decide If There Is an Association

Essay

In an effort to decide if there is an association between the year of a postal increase and the new postal rate for first class mail, the data were gathered from the United States Postal Service. In 1981, the United States Postal Service changed their rates on March 22 and November 1. This information is shown in the table below.

$\begin{array}{|c|c|}\hline \text {Year} &\text { Rate} \\\hline 1971 & 0.08 \\\hline 1974 & 0.10 \\\hline 1975 & 0.13 \\\hline 1978 & 0.15 \\\hline 1981 & 0.18 \\\hline 1981 & 0.20 \\\hline 1985 & 0.22 \\\hline 1988 & 0.25 \\\hline 1991 & 0.29 \\\hline 1995 & 0.32 \\\hline\end{array}$

-Would it be better for customers for a year to have a negative residual or a positive residual from this model? Explain.