Given the following data

dataset for plotting grade tonnage curves:

$*$Grade Tonnage Curve Data$*$

$|$ Ash Content $(\%)|$ Cumulative Tonnage $($million tons$)|$ Grade $(\%)|$

$|---|---|---|$

$|10|0\mathrm{.}1|6\mathrm{.}5|$

$|12|0\mathrm{.}3|6\mathrm{.}2|$

$|15|0\mathrm{.}5|5\mathrm{.}9|$

$|18|1\mathrm{.}0|5\mathrm{.}5|$

$|20|1\mathrm{.}5|5\mathrm{.}2|$

$|22|2\mathrm{.}2|4\mathrm{.}9|$

$|25|3\mathrm{.}0|4\mathrm{.}5|$

$|28|4\mathrm{.}0|4\mathrm{.}1|$

$|30|5\mathrm{.}0|3\mathrm{.}8|$

$|32|6\mathrm{.}0|3\mathrm{.}5|$

$|35|7\mathrm{.}0|3\mathrm{.}2|$

$*$Density Curve Data$*$

$|$ Density $($g$/$cm$3)|$ Cumulative Tonnage $($million tons$)|$

$|---|---|$

$|1\mathrm{.}3|0\mathrm{.}5|$

$|1\mathrm{.}4|1\mathrm{.}2|$

$|1\mathrm{.}5|2\mathrm{.}5|$

$|1\mathrm{.}6|4\mathrm{.}0|$

$|1\mathrm{.}7|5\mathrm{.}5|$

$|1\mathrm{.}8|7\mathrm{.}0|$

$*$Yield Curve Data$*$

$|$ Ash Content $(\%)|$ Yield $(\%)|$

$|---|---|$

$|20|80|$

$|22|75|$

$|25|70|$

$|28|65|$

$|30|60|$

plot:

$1.$ Grade Tonnage Curve

$2.$ Density Curve

$3.$ Yield Curve