Question 723900
They say the relation is linear, which means
a straight line. Use the general point-slope formula.
Plot {{{ c }}} on the vertical axis and {{{ t }}}
on the horizontal axis.
For the year 2000, make {{{ t = 0 }}}
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given:
{{{ ( c - 12700 ) / ( t - 0 ) = ( 15100 - 12700 ) / ( 3 - 0 ) }}}
{{{ ( c - 12700 ) / t = 2400 / 3 }}}
{{{ ( c - 12700 ) / t = 800 }}}
{{{ c - 12700 = 800t }}}
{{{ c = 800t + 12700 }}}
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check:
( 0,12700)
{{{ c = 800t + 12700 }}}
{{{ 12700 = 800*0 + 12700 }}}
{{{ 12700 = 12700 }}}
OK
(3,15100)
{{{ c = 800t + 12700 }}}
{{{ 15100 = 800*3 + 12700 }}}
{{{ 15100 = 2400 + 12700 }}}
{{{ 15100 = 15100 }}}
OK
In 2007, {{{ t = 7 }}}
{{{ c = 800t + 12700 }}}
{{{ c = 800*7 + 12700 }}}
{{{ c = 5600 + 12700 }}}
{{{ c = 18300 }}}
In 2007, the average cost will be $18,300