What is a placebo, and why is it important in an experiment to test the effectiveness of a drug?
What is a placebo?
A.
A placebo refers to a specific member of a sample from which data are collected.
B.
A placebo refers to a situation in which a patient improves simply because they believe they are receiving a useful treatment.
C.
A placebo refers to any problem in the design or conduct of a statistical study that tends to favor certain results.
D.
A placebo is physically similar to a treatment, but it lacks any active ingredients, so it should not by itself produce any effects.

I think it’s b hope it helps and if it did pls mark me as brainliest pls

Step-by-step explanation:

A placebo is used in clinical trials to test the effectiveness of treatments and is most often used in drug studies. ... This way, the researchers can measure if the drug works by comparing how both groups react. If they both have the same reaction — improvement or not — the drug is deemed not to work.

answer: expected value of x = 1.0

step-by-step explanation:

p(x=0) = 0.25

p(x=1) = 0.50

p(x=2) = 0.25

expected value for x = 0×0.25 + 1×0.5 + 2×0.25 = 1.0

the answer is d

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