Critical Reasoning

Can someone please explain to me?

In 1987 sinusitis was the most common chronic medical condition in the United States, followed by arthritis
and high blood pressure, in that order.
The incidence rates for both arthritis and high blood pressure increase with age, but the incidence rate for
sinusitis is the same for people of all ages.
The average age of the United States population will increase between 1987 and 2000.
Which of the following conclusions can be most properly drawn about chronic medical conditions in the
United States from the information given above?
(A) Sinusitis will be more common than either arthritis or high blood pressure in 2000.
(B) Arthritis will be the most common chronic medical condition in 2000.
(C) The average age of people suffering from sinusitis will increase between 1987 and 2000.
(D) Fewer people will suffer from sinusitis in 2000 than suffered from it in 1987.
(E) A majority of the population will suffer from at least one of the medical conditions mentioned above by the
year 2000.

Nidhs wrote:Can someone please explain to me?

In 1987 sinusitis was the most common chronic medical condition in the United States, followed by arthritis
and high blood pressure, in that order.
The incidence rates for both arthritis and high blood pressure increase with age, but the incidence rate for
sinusitis is the same for people of all ages.
The average age of the United States population will increase between 1987 and 2000.
Which of the following conclusions can be most properly drawn about chronic medical conditions in the
United States from the information given above?
(A) Sinusitis will be more common than either arthritis or high blood pressure in 2000.
(B) Arthritis will be the most common chronic medical condition in 2000.
(C) The average age of people suffering from sinusitis will increase between 1987 and 2000.
(D) Fewer people will suffer from sinusitis in 2000 than suffered from it in 1987.
(E) A majority of the population will suffer from at least one of the medical conditions mentioned above by the
year 2000.

In this question we're asked which answer is a reliable conclusion that can be drawn, based on the information provided.

On inference questions, we have to be very careful not to read too deeply into the stimulus. We're looking for an answer that MUST BE TRUE based on only the information provided.

In the stimulus, we're told that:

in 1987, S is the most common condition, followed by A and H.

A and H are both more common as people get older; S is equally common among all age groups.

The average age in the US will increase from 1987 to 2000.

Let's examine the choices, asking ourselves, for each one, does this HAVE TO BE TRUE?

(a) We know that S is more common now, but we don't know how rapidly A and H increase with age. It's possible that either A or H will pass S by 2000. (a) might be true, but that's not good enough: eliminate (a).

(b) Just as in (a), A could turn out to be the most common as people get older, but we don't know for sure: eliminate (b).

(c) We know that S is equally common among all age groups. If the average age of people increases, then incidents of S will ride the age wave and the average age of people with S will also increase. (c) MUST be true: pick (c).

(d) We don't know whether overall population will increase or decrease, we only know about average age. Without info about the numbers, there's no way to predict if more or fewer people will get S: eliminate (d).

(e) We know nothing about the actual % of people who suffer from each disease - it could be 80%, 70% and 60% or it could be 8%, 7% and 6%. Without the actual %s, there's no way to predict what proportion of the population will suffer from S, A or H: elminate (e).

thanks, stuart

Stuart Kovinsky wrote:

Nidhs wrote:Can someone please explain to me?

In 1987 sinusitis was the most common chronic medical condition in the United States, followed by arthritis
and high blood pressure, in that order.
The incidence rates for both arthritis and high blood pressure increase with age, but the incidence rate for
sinusitis is the same for people of all ages.
The average age of the United States population will increase between 1987 and 2000.
Which of the following conclusions can be most properly drawn about chronic medical conditions in the
United States from the information given above?
(A) Sinusitis will be more common than either arthritis or high blood pressure in 2000.
(B) Arthritis will be the most common chronic medical condition in 2000.
(C) The average age of people suffering from sinusitis will increase between 1987 and 2000.
(D) Fewer people will suffer from sinusitis in 2000 than suffered from it in 1987.
(E) A majority of the population will suffer from at least one of the medical conditions mentioned above by the
year 2000.

In this question we're asked which answer is a reliable conclusion that can be drawn, based on the information provided.

On inference questions, we have to be very careful not to read too deeply into the stimulus. We're looking for an answer that MUST BE TRUE based on only the information provided.

In the stimulus, we're told that:

in 1987, S is the most common condition, followed by A and H.

A and H are both more common as people get older; S is equally common among all age groups.

The average age in the US will increase from 1987 to 2000.

Let's examine the choices, asking ourselves, for each one, does this HAVE TO BE TRUE?

(a) We know that S is more common now, but we don't know how rapidly A and H increase with age. It's possible that either A or H will pass S by 2000. (a) might be true, but that's not good enough: eliminate (a).

(b) Just as in (a), A could turn out to be the most common as people get older, but we don't know for sure: eliminate (b).

(c) We know that S is equally common among all age groups. If the average age of people increases, then incidents of S will ride the age wave and the average age of people with S will also increase. (c) MUST be true: pick (c).

(d) We don't know whether overall population will increase or decrease, we only know about average age. Without info about the numbers, there's no way to predict if more or fewer people will get S: eliminate (d).

(e) We know nothing about the actual % of people who suffer from each disease - it could be 80%, 70% and 60% or it could be 8%, 7% and 6%. Without the actual %s, there's no way to predict what proportion of the population will suffer from S, A or H: elminate (e).

@Stuart - Though I agree to your logic, don't you think you are missing out on the new incidences of sinus. Younger kids can also get affected and the average age don't have to necessarily increase. Pls correct me if m wrong.

msr4mba wrote:
@Stuart - Though I agree to your logic, don't you think you are missing out on the new incidences of sinus. Younger kids can also get affected and the average age don't have to necessarily increase. Pls correct me if m wrong.

Hi,

the question stem tells us to draw a conclusion "from the information given above". Two of those pieces of info are:

The incidence rates for both arthritis and high blood pressure increase with age, but the incidence rate for sinusitis is the same for people of all ages.

and

The average age of the United States population will increase between 1987 and 2000.

So, we do definitely know that the average age will increase over that time period.