Question

Physicians at a clinic gave what they thought were drugs to 860 patients. Although the doctors later learned that the drugs were really placebos,59% of the patients reported an improved condition. Assume that if the placebo is ineffective, the probability of a patients condition improving is 0.55. Test the hypotheses that the proportion of patients improving is >0.55
Find the test statistics:

z=


Find the p-value.
p=

Answer 1

Answer:

Z=2.36

P=0.0091

Step-by-step explanation:

The hypothesis is:

π > 0.55 which is the population proportion

The formula to get the test statistic is

Zstat = P-π/√π(1-π)/n

P =507.4/860 = 0.59 (sample proportion )

n =860 (sample size)

π =0.55(population porportion)

Zstat = 0.59-0.55/√0.55(1-0.55)/860

Zstat =2.36

From Z table the probability of Z score of 2.36 is 0.9909

To calculate for P- value will then be

P= 1 - 0.9909

P= 0.0091