Question

Is the Medicine Working?

An independent medical researcher recorded whether patients showed improvement or no improvement in their medical condition. Each patient either received medicine or a placebo. Each patient received treatment for the same amount of time and were exposed to the same living conditions. The results are shown in the two-way table.

Medicine Placebo Total
Improvement 2,800 2,200 5,000
No Improvement 2,200 2,800 5,000
Total 5,000 5,000 10,000
The medical researcher concluded that the medicine will cause significant improvement in a patient’s medical condition.

Question
Use the data report on the left to answer the questions.

Is the conclusion in the data report valid? Why or why not?

(1 point)
Responses

The conclusion is valid because the data report does not show design flaws or major bias, and it is supported by the data.
The conclusion is valid because the data report does not show design flaws or major bias, and it is supported by the data.

The conclusion is not valid because even though the data report does not show design flaws or major bias, the conclusion is supported by the data.
The conclusion is not valid because even though the data report does not show design flaws or major bias, the conclusion is supported by the data.

The conclusion is valid because the data report shows design flaws and major bias, and it is not supported by the data.
The conclusion is valid because the data report shows design flaws and major bias, and it is not supported by the data.

The conclusion is not valid because even though the data report does not show design flaws or show major bias, the conclusion is not supported strongly enough by the data.
The conclusion is not valid because even though the data report does not show design flaws or show major bias, the conclusion is not supported strongly enough by the data.

Answer 1

The conclusion is valid because the data report shows no design flaws or major bias and the data strongly support it.

Explanation (brief): Improvement rates are 2,800/5,000 = 56% for medicine vs 2,200/5,000 = 44% for placebo (difference = 12 percentage points). With n1 = n2 = 5,000 the standard error for the difference (under the null) ≈ 0.01, so z ≈ 0.12/0.01 = 12, giving a p-value ≈ 0 (highly significant).