A recent survey of women diagnosed with breast cancer found that 85...

Question

A recent survey of women diagnosed with breast cancer found that 85 percent of them reported wearing a brassiere on a regular basis. One possible conclusion is that wearing a brassiere can cause breast cancer.

To evaluate the conclusion above, it would be useful to know the answer to all of the following questions EXCEPT:

A) Did the women surveyed have any known risk factors for breast cancer such as cigarette smoking, sedentary lifestyles or high-fat, high-cholesterol diets?
 B) What is the percentage of women who report wearing a brassiere on a regular basis yet never develop breast cancer?
 C) What is the percentage of women in the general population who report wearing a brassiere on a regular basis?
 D) Given that a predisposition for breast cancer can be inherited, did the women surveyed have a family history of the disease?
 E) What percentage of women who report wearing a brassiere on a regular basis are diagnosed with other types of cancer?

NRJ11090 · Answer

IMO E. 
E here discusses percentage of women who report wearing a brassiere on a regular basis are diagnosed with  other types of cancer 
We don't need information for other types of cancer and it is because of this reason that E seems to be irrelevant and hence, the correct answer choice.

Arro44 · Answer

I would say our correct answer choice here is option E.

Answers to all other statements would provide us with additional information to put the original conclusion into perspective.

However, as we are talking about bras potential effect on developing breast cancer, it is totally irrelevant to learn about its potential relation to other causes of cancer. Therefore, I would argue that "E" is the clear winner due to irrelevancy.

Hope this helps.

Regards,
Chris

artiom01 · Answer

Could anyone point out why  C  could be usefull to evaluate the statement?

Arro44 · Answer

C would be helpful as it allows you to put the initial information into perspective.

It would enable to draw a conclusion based on how the facts look in comparison. Best regards, Chris

budhni · Answer

please explain how C would be helpful as it allows you to put the initial information into perspective.

FilippoSerlupi · Answer

Assume that 85% of the general population wears the bra: it means that there is absolutely no correlation with the fact that wearing the bra causes breast cancer.
If, on the contrary, we assume that only 10% of the population wears it, this strengthens the assumption that wearing a bra causes breast cancer

Sneha2021 · Answer

How A is useful to evaluate the argument? How is knowing the risk factors strengthen the conclusion?

A) Did the women surveyed have any known risk factors for breast cancer such as cigarette smoking, sedentary lifestyles or high-fat, high-cholesterol diets?

Please help.

KeyurJoshi · Answer

A recent survey of women diagnosed with breast cancer found that 85 percent of them reported wearing a brassiere on a regular basis. One possible conclusion is that wearing a brassiere can cause breast cancer.

To evaluate the conclusion above, it would be useful to know the answer to all of the following questions EXCEPT:

Lets test the extreme cases for each choice. This should give us opposing answers.

A) Did the women surveyed have any known risk factors for breast cancer such as cigarette smoking, sedentary lifestyles or high-fat, high-cholesterol diets?

YES. the women surveyed have any known risk factors for breast cancer such as cigarette smoking, sedentary lifestyles or high-fat, high-cholesterol diets. That means we have a reason to believe that wearing brassiere does NOT cause breast cancer.
NO. the women surveyed did NOT have any known risk factors for breast cancer such as cigarette smoking, sedentary lifestyles or high-fat, high-cholesterol diets. That means we have a reason to believe that wearing brassiere does cause breast cancer.
Eliminate.

B) What is the percentage of women who report wearing a brassiere on a regular basis yet never develop breast cancer?

Say, 99% of women who report wearing a brassiere on a regular basis yet never develop breast cancer. That means we have a reason to believe that wearing brassiere does NOT cause breast cancer.

Say 1% of women who report wearing a brassiere on a regular basis yet never develop breast cancer. That means there are other majority of cases in which breast cancer has developed. So we have a reason to believe that wearing brassiere does cause breast cancer.
Eliminate

C) What is the percentage of women in the general population who report wearing a brassiere on a regular basis?

Although is E is completely irrelevant, I wanted to know why this choice was incorrect. Now I'm not so sure if my explanation is right but if I put some numbers here's what I found.
Also, here, we dont know how many women having breast cancer were actually surveyed. We will take hypothetical numbers. Please refer to the attached image in this case.
Women who have breast cancer = 200
Total women with and without breast cancer = 1000

Case (I)
Say there are 80% of women in the general population who report wearing a brassiere on a regular basis
We see that Women who wear brassiere on regular basis but do not have breast cancer > Women who wear brassiere on regular basis and have breast cancer (630 > 170) Here, we have a reason to believe that wearing brassiere does not cause breast cancer.

Case (II)
Say there are only 20% of women in the general population who report wearing a brassiere on a regular basis.
We see that Women who wear brassiere on regular basis but do not have breast cancer < Women who wear brassiere on regular basis and have breast cancer (30 < 170) Here, we have a reason to believe that wearing brassiere MAY cause breast cancer.

D) Given that a predisposition for breast cancer can be inherited, did the women surveyed have a family history of the disease?
Yes, the women surveyed have a family history of the disease. So maybe the breast cancer has inherited in these women.
No, the women surveyed did not have a family history of the disease. That means the cause might've been wearing brassiere itself.

Eliminate.

E) What percentage of women who report wearing a brassiere on a regular basis are diagnosed with other types of cancer?

Say, 99% of women who report wearing a brassiere on a regular basis are diagnosed with other types of cancer. For e.g. 99% woman wearing brassiere may have skin cancer and breast cancer.
and Say 1% of women who report wearing a brassiere on a regular basis are diagnosed with other types of cancer. For e.g. 1% woman wearing brassiere may have skin cancer and breast cancer.

But this DOES NOT rule out the possibility that wearing brassiere causes breast cancer in either of the above cases regardless of the percentage of diagnosis with other type of cancer.

CORRECT.

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