sandy wrote:

Attachment:

#GREpracticequestion If it were discovered that the value of imports shown.jpg

If it were discovered that the value of imports shown for 2007 was incorrect and should have been $5 billion instead, then the average (arithmetic mean)value of imports per year for the 10 years shown would have been approximately how much less?

A $200 million

B $50 million

C $20 million

D $7 million

E $5 million

Given: The graph shows $7 billion for 2007, when it should actually be $5 billion.

One way to solve this question is to estimate the imports for all 10 years (with $7 billion for 2007), and then find the average.

Then estimate the imports for all 10 years (with $5 billion for 2007), and then find the average

Then find the difference between those averages.

This is more work than we need to do.

Since 9 of the values don't change, we can let x = the sum of those 9 values.

Now we'll find two averages:

Average value when we use $7 billion for 2007 = (x + 7)/10Average value when we use $5 billion for 2007 = (x + 5)/10So, the DIFFERENCE =

(x + 7)/10 -

(x + 5)/10= (

x/10 + 7/10) - (

x/10 + 5/10)

= 2/10 (billion dollars)

= 200 million dollars

Answer: A

Cheers,

Brent

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Brent Hanneson – Creator of greenlighttestprep.com

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