Question 432714
What you need to do is plot a a straight line that
goes through the points (52, 4.91) and (64,5.87)
Notice that cans, {{{c}}}, are plotted on the horizontal 
and Earnings, {{{e}}}, are on the vertical.
The formula is:
{{{ (e - 4.91)/(c - 52) = (5.87 - 4.91)/(64 - 52) }}}
{{{ (e - 4.91)/(c - 52) = .96/ 12 }}}
{{{ 12*(e - 4.91) = .96*(c - 52) }}}
{{{ 12e - 58.92 = .96c - 49.92 }}}
{{{ 12e = .96c + 9 }}}
{{{ 4e = .32c + 3 }}} answer
check answer:
{{{c = 52}}}
{{{ 4e = .32*52 + 3 }}}
{{{ 4e = 16.64 + 3 }}}
{{{ 4e = 19.64 }}}
{{{ e = 4.91 }}}
OK
(b)
107 cans
{{{ 4e = .32*107 + 3 }}}
{{{ 4e = 34.24 + 3 }}}
{{{ 4e = 37.24 }}}
{{{ e = 9.31 }}}
(c)
$7.87
{{{ 4*7.87 = .32c + 3 }}}
{{{ 31.48 = .32c + 3 }}}
{{{ .32c = 28.48 }}}
{{{ c = 89 }}}