You have to divide denominator by numerator to find the constant of proportionality.
2%
take the absolute value of your (experimental-accepted then divide by the accepted) so (20-25)/25=.2
then multiply that number by 100 to get the percent, .2*100=2
3 because the numbers for x are all different

Get x to one side
So minus 90 from each side

-90÷-3=30
Answer: x=30