Calculating Trump's Approval Rating for Non-Republicans My father asked me this question yesterday, and as a math major I was a little embarrassed that I was not immediately sure that the answer I obtained was correct. He asked: > If President Trump's overall approval rating is 38% among 125 million total voters, and the approval rating among the 56 million republican voters is 80%, then what is the approval rating of the other 69 million non-republican voters? Is this a weighted averages sort of problem? I set up my equation as: $$0.448\times 0.8 + 0.552 \times x = 0.38$$ Thus $$x= 0.039$$ giving an approval rating of 3.9%. Is this correct?

Yes, this is correct. Maybe this will be more clear:

Total number of approvals: $0.38 \times 125 = 47.5$

Number of approvals among republicans: $0.8 \times 56 = 44.8$

Number of approvals among non-republicans: $x \times 69$

$47.5 = 44.8 + x \times 69$

$x = 0.039$