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
_________________
Brent Hanneson – Creator of greenlighttestprep.com
Sign up for GRE Question of the Day emails