Question

A certain drug is used to treat asthma. In a clinical trial of the drug, 21 of 250 treated subjects experienced headaches (based on data from the

manufacturer). The accompanying calculator display shows results from a test of the claim that less than 8% of treated subjects experienced
headaches. Use the normal distribution as an approximation to the binomial distribution and assume a 0.01 significance level to complete parts (a)
through (e) below
a. Is the test two-tailed, left-tailed, or right-tailed?
1-PropzTest
prop<0.08
z=0.233126
D=0.592168

Answer 1

a) The test is left-tailed.

Explanation:

a) Hypothesis testing is tagged two-tailled if the test checks for a claim in both directions (greater than and less than).

It is one tailed if it checks for a claim in only one direction (either greater than or less than). It is left-tailed of it is testing the claim in a less than direction and right-tailed if it is testing the claim in a greater than direction.

This question is to check results from a test of the claim that less than 8% of treated subjects experienced headaches. It is evidently left tailed.

Hope this Helps!!!