Think of 4.2 as the part and we are looking for the whole.
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Practice makes perfect
The percent proportion is a proportion that equates a part of a whole to a percent out of 100.
a/b=p/100
In this form, a is the part and b is the whole. In our case, we are thinking about 4.2 as part of a whole and our missing number is the whole amount. Therefore, we can find b by substituting a= 4.2 and p= 20 into the formula and solving for b.
