It can't be A because of the fact that by multiplying 445 by "x" you'll get a higher, postitive number. Meaning that if adding that positive number, you'll get something higher than 18,259. Which isn't our goal. In addition, the key word is "depreciates" which is another word for subtracting. However, that only applies in some circumstances. It can't be D either since you're basically adding a negative number by another negative number. However, "18,259" has to be a positive in this problem. By that you can also eliminate C as well. Meaning that B would be the correct answer.
Step-by-step explanation: ok so first to find the mean you add all the numbers then divide by how many numbers there is so basically 18 plus 15 plus 20 plus 15 then divide by 4 because there is 4 numbers and once you do that it is 17