NEED HELP!!!!....BUT....WANT TO LEARN!!....

Question

THE AVERAGE AMOUNT OF ANNUAL INTEREST EARNED ACROSS THREE INVESTMENT ACCOUNTS WAS $2709.00 IF ONE ACCOUNT YIELDED $1345.00 IN THE TWELVE MONTH PERIOD, AND THE SECOND YIELDED $568.00 WHAT DID THE THIRD ACCOUNT YIELD?

 

 

 

A) $1913.00

 

B) $4622.00

 

C) $5739.00

 

D) $6214.00

Answer 1

Hello Leanice,

 

Since average is defined as the total of all items divided by the number of items in the set, and there are 3 investments, we can set up the following equation with x as the value of the unknown yield.

 

(1345+568+x)/3=2709

 

Combine like terms

(1913+x)/3=2709

 

Multiply both sides by 3

1913+x=8197

 

Subtract 1913 from both sides

x=6214

Answer 2

Alas, this problem has TMI  (too much information)  -- it may be meant to confuse you.

Could we just talk numbers (not investment accounts) and use dollars (instead of dollars and cents) and just say:
       The average is of three numbers is 2709.   One number is 1345.  Another is 568.  What is the third?

 

               2709  =(1345 + 568 + x)/3

So,       8127 = 1345 + 568 + x
                     $6214.00 = x

Checking:

      Is    2709  = (1345 + 568 +6214)/3     ?    yes

 

p.s., keep wanting to learn, it is sometimes hard for teachers/tutors to find "that teachable moment"