Answer:
![x + 18.99 \leq 24](https://img.qammunity.org/2020/formulas/mathematics/middle-school/mi7n7xbkm56lhs0113fdukjd0i84yfuotf.png)
Explanation:
Since, the cost of bus fair = x dollars,
Also, a baseball cap which is $18.99 is needed to buy with the given money,
Hence, total expenditure = x + 18.99
While the given money for spending = 24 dollars,
That is, the expenditure can not be exceeded to $ 24.
Thus, the required inequality,
![x + 18.99 \leq 24](https://img.qammunity.org/2020/formulas/mathematics/middle-school/mi7n7xbkm56lhs0113fdukjd0i84yfuotf.png)