Answer:
Choice C: 6%
Explanation:
Totoal worth of dimes in Stephen's piggy bank is $6 and the total amount is
7.50 + 6.00 + 5.50 + 3.00 = 22; thefore the ratio of dimes worth to total worth is

which can be simplified and written as

And as a percentage this is

We see here that there are three ways to represent the comparison of dimes worth to total worth: 6/22, 3/11, and 27%. Hence, it is choice C that does not accurately represent the comparison, and therefore, it is the right choice.