Given:
When all the students behave well then Ms. Lee reward them by drawing stars on a chart.
The chart has 200 or more starts the class has a party.
Now, the class has 28 stars.
The inequality is,
[tex]28+x\ge200[/tex]Now, solve the inequality,
[tex]\begin{gathered} 28+x\ge200 \\ x\ge200-28 \\ x\ge172 \end{gathered}[/tex]That means the class need 172 or more to be rewarded to earn a party.