A survey claims that 9 out of 10 doctors recommend aspirin for their patients with headaches.To
Test this claim against the alternative that the actual proportion of doctors who recommend aspirin
Is less than 0.90, a random sample of 100 doctors results in 83 who indicate that they recommend
Aspirin.The value of the test statistic in this problem is approximately equal to:
A) - 4.12
B) - 2.33
C) - 1.86
D) - 0.07

Question

Quizplus · Accepted Answer

The test statistic is calculated using the formula for a proportion: $ z = \frac{\hat{p} - p_0}{\sqrt{\frac{p_0(1-p_0)}{n}}} $, where $\hat{p} = 0.83$, $p_0 = 0.90$, and $n = 100$. Plugging in these values gives approximately -2.33.

A Survey Claims That 9 Out of 10 Doctors Recommend