The polynomial function $M(t)=0\mathrm{.}7t^4+1\mathrm{.}06t^3-89\mathrm{.}85t^2+350\mathrm{.}05t,0t6,$ estimates the number of milligrams of ibuprofen in the bloodstream thours after $400mg$ of medication has been swallowed.

Use the graph to estimate the number of milligrams of ibuprofen in the bloodstream $4$ hours after $400mg$ has been swallowed.

The amount is $mg.$

$($Round your answer to the nearest ten.$)$