The total amount of consumer credit has been increasing steadily in recent years. The following table gives the total outstanding consumer credit (in billions of dollars). Answer parts (a) through (e) below.
\begin{tabular}{|c|c|c|c|}
\hline Year & $\begin{array}{c}\text { Consumer } \\
\text { Credit }\end{array}$ & Year & $\begin{array}{c}\text { Consumer } \\
\text { Credit }\end{array}$ \\
\hline 2003 & 2219.5 & 2008 & 2553.5 \\
\hline 2004 & 2319.8 & 2009 & 2645.1 \\
\hline 2005 & 2415.0 & 2010 & 2756.0 \\
\hline 2006 & 2551.9 & 2011 & 2926.3 \\
\hline 2007 & 2595.1 & 2012 & 3099.2 \\
\hline
\end{tabular}
a. Find an equation for the least squares line, letting $x$ equal the number of years since 2001.
The equation is $Y=85.49 \mathrm{X}+2052.46$.
(Use integers or decimals for any numbers in the equation. Round to two decimal places as needed.)
b. Based on the answer to part (a), at approximately what rate is consumer credit growing per year?
The consumer credit is growing about $\$$ billion per yeàr.
(Round to two decimal places as needed.)
Answer
So, the final answer is \(\boxed{85.49}\).
Step 1 ：The equation for the least squares line is given as \(Y=85.49X+2052.46\).
Step 2 ：The slope of the least squares line represents the average increase in consumer credit per year.
Step 3 ：The slope of the line is given as 85.49, which means that on average, consumer credit is increasing by \$85.49 billion per year.
Step 4 ：So, the final answer is \(\boxed{85.49}\).
