The correct answer is B. Most patients who have a poor dental experience also have post-extraction complications. This can be shown through the fact that of everyone who had a poor dental experience, 94% said they had post-extraction complication. 94% is obviously <em>most</em>. We can not confidently say that poor dental experiences cause post-extraction problems because we do not know how many people who had a normal or good experience also had problems.
First calculate total payments
18×95.25=1,714.5
After that to find the interest you just subtract the amount borrowed from the total payments
Interest=1,714.5−1,450=264.5
Hope it helps!