Question 1019908
The number of empty seats is 250 - 225 = 25, the total capacity minus those
already filled.
The percentage empty is just {{{25/250}}} = {{{1/10}}} converted to
percent which gives us 10%

Your proportion {{{225/250 = x/100}}} is the proportion of the theater
that is filled.
The correct proportion would be {{{(250-225)/250 = x/100}}} or
{{{(25)/250 = x/100}}}
The cross product here is 25x = 2500
Divide each side by 25
x = 10 percent