Factinate claims that 84% of teenagers think highly of their mother. To investigate this claim, a school psychologist selects a random sample of 150 teenagers and finds that 135 think highly of their mother. Does this data provide convincing evidence that the true proportion of teens who think highly of their mother is greater than 0.84

To find the amount that Franklin financed, you will calculate the amount he put down and subtract that from the original price because that is what he still owes.

0.2 x $4500 = $900
$4500 - $900 = $3600.

Porter financed $3600.

You also multiply 0.8 x $4500 because this represents the part out of 100% he still owes.  You will get the same answer this way.