Answer
LaTonya will pay $\$ 157.50$
Work Step by Step
Typical percentage problem:
What percent ($n$, as a decimal number) of (the base amount $y)$ is $x?$
Translated:$\quad n\cdot y=x$
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Here, reworded, $\quad 4.50\%$ of ($y=3500$) is ($x=?$).
Translated:$\quad 0.045\cdot 3500=x$
($ 4.50\%$ converted to decimal notation is $0.045)$
$x=157.50$