Answer
$(a)$ See the image below
$(b)$ $y=0.27083x-462.9$
$y$ stands for the life expectancy and $x$ stands for the year
$(c)$ $\approx80.4$
$(d)$ According to the data provided by World Bank, the average life expectancy in the United States in the year 2006 was approximately $77.7$. Compared to the expectation of $80.4$ in $(c)$, it's low.
Work Step by Step
$(a)$ See the image above
$(b)$ We can find them using regression line calculator and graphing calculator (see the image above):
$y=0.27083x-462.9$
$y$ stands for the life expectancy and $x$ stands for the year
$(c)$ If $x=2006$
$y=0.27083\times2006-462.9\approx80.4$
$(d)$ According to the data provided by World Bank, the average life expectancy in the United States in the year 2006 was approximately $77.7$. Compared to the expectation in $(c)$ it's low.
