A set of 200 independent patients take antiacid medication at the start of symptoms, and 80 experience moderate to substantial relief within 90 minutes. Historically, 30% of patients experience relief within 90 minutes with no medication. If the medication has no effect, approximate the probability that 80 or more patients experience relief of symptoms. What can you conclude about the effectiveness of this medication?

Step 1 of 2:

Given n = 200,

P = the probability of success in each trial

Let X = binomial random variable of patients experiencing relief from symptoms.

Normal approximation is good for np > 5, and n(1-p) >5.

Then,

np = 200(0.4) = 80 > 5 and

n(1-p) = 200(1-0.4) = 120 > 5.

Z = standard normal random variable