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F. Incorrect. Substitute $t=3$ into all terms of the given equation. Make sure to keep track of the signs on the terms. 

G. Correct. Substitute $t=3$ into all terms of the given equation: $h\left(3\right)=-4.9\left(3^2\right)+30\left(3\right)+55=100.9$.

H. Incorrect. Substitute $t=3$ into all terms of the given equation. You may have calculated and added only the middle and last terms of the equation, $30\left(3\right)+55=145$.

J. Incorrect. Substitute $t=3$ into all terms of the given equation. You may have calculated the terms correctly, but missed the negative sign on the first term: $4.9\left(3^2\right)+30\left(3\right)+55=189.1$.