Chapter 15, Problem 6T

To determine

The population, in the year $1975$, of the United States from the provided data,

Year	Population $\left(\text{in thousands}\right)$
$1940$	$132,594$
$1950$	$152,271$
$1960$	$180,671$
$1970$	$204,879$
$1980$	$227,757$
$1990$	$249,246$
$2000$	$281,422$
$2010$	$308,746$