OG 2016 CR D24

[burns.nelson]

I can't post in any Verbal forums. Apologies for posting here. In OG 2016, CR D24 on page 35, can someone please provide an example or clarify how to make sense of "The percentage of households with an annual income of more than $40,000 is higher in Merton County than any other county. However, the percentage of households with an annual income of $60,000 or more is higher in Sommer County."

I'm having difficulty understanding the possibilities of income of more than 40K versus income of 60K or more.

Thank you.

[AndrewR3]

Merton [list=]
Total population = 20
Population (<40K) = 10
Population (40K ≤ X ≤60) = 7
Population ( X ≥60) = 3
% (≥ 40 K) = 50% (10/20)
% (> 60K) = 15% (3/20)
[/list]

Sommer [list=]
Total population = 10
Population (<40K) = 7
Population (40K ≤ X ≤60) = 0
Population ( X ≥60) = 3
% (≥ 40 K) = 30% (3/10)
% (≥ 60K) = 30% (3/10)
[/list]

% ≥ 40 K
Merton = 50% vs. Sommer = 30%

% ≥ 60K
merton = 15% vs. Sommer = 30%

[StaceyKoprince]

Nobody can post in any of the OG forums. The owners of the GMAT no longer legally permit their questions to be reproduced online (unless those questions are already given away for free, such as the GMAT Prep free exams). Those forums were locked when the company invoked its copyright back in 2007 or so, if I remember the date correctly.

We do have a product called GMAT Navigator, in which we give our own solutions to many of the OG problems - but we don't unfortunately have any solutions for the CR problems in the diagnostic section of the book. (Also, you have to have your own copy of the OGs to use this product - we can't reproduce the full question text in that product either. Basically, that stuff is only legally allowed to be in the books / materials produced by the copyright owners.)

Andrew is providing a mathematical example. If that works for you, great (and thanks Andrew!).

If that makes your brain hurt, try drawing out some hypothetical examples to see how those statistics work. (This is basically what Andrew did, but some people find that harder to follow if they don't draw / think it out themselves.)