All of the following are equivalent except

4%
0.04
0.4
1/25

From the start you notice one of the decimals must not be equivalent.   you notice this because 0.4 and 0.04 are not the same.   so you can do one of two things.   convert the percent into a decimal by moving the decimal point (currently hidden right here 4.0%) two places to the left,   or you can divide the numerator by the denominator of the fraction.   either way,   you get 0.04.   the odd one out is 0.4,   because it equals 40%

0.4 is not equivalent to the others. all of the others equal 0.04. 4% = 4/100 = 0.04 = 4/100 = 1/25