Michelle's score is given by the following formula
[tex]S=2\cdot C[/tex]where, S is her final score and C represent the number of correct answers.
Since she must get at least a 92, then S = 92
therefore,
[tex]\begin{gathered} 92=2\cdot C \\ C=\frac{92}{2} \\ C=46 \end{gathered}[/tex]She must get at least 46 correct questions.