Question 1083314
Plot {{{ E }}} on the vertical axis
Plot {{{ t }}} on the horizontal axis
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Call year 1993 {{{ t = 0 }}}
That makes 1998 {{{ t = 5 }}}
So, you are given the 2 points:
( 0, 73.6 )
( 5, 77.2 )
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You can use the general point-slope formula
{{{ ( 77.2 - E ) / ( 5 - t ) = ( 77.2 - 73.6 ) / ( 5 - 0 ) }}}
{{{ ( 77.2 - E ) / ( 5 - t ) = 3.6 / 5 }}}
Multiply both sides by {{{ 5*( 5 - t ) }}}
{{{ 5*( 77.2 - E ) = 3.6*( 5 - t ) }}}
{{{ 386 - 5E = 18 - 3.6t }}}
{{{ 5E = 3.6t + 368 }}}
{{{ E = .72t + 73.6 }}}
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check answer:
Does it go through ( 5, 77.2 ) ?
{{{ E = .72t + 73.6 }}}
{{{ 77.2 = .72*5 + 73.6 }}}
{{{ 77.2 = 3.6 + 73.6 }}}
{{{ 77.2 = 77.2 }}}
OK
Does it go through ( 0, 73.6 ) ?
{{{ E = .72t + 73.6 }}}
{{{ 73.6 = .72*0 + 73.6 }}}
{{{ 73.6 = 73.6 }}}
OK