Answer
The percent is $1333.\overline3\%$.
Work Step by Step
Plug the values into this equation, where b is one value, p is the percent, expressed as a decimal, and a is p percent of b.
$a=p\%\times b$ substitute
$400=p\%\times30$ divide both sides by 30
$400\div30=p\%\times30\div30$ simplify
$13.\overline3=p\%$ convert from a decimal to a percent
$1333.\overline3=p\%$
