In a study of treatments for very painful \"cluster\" headaches, 140 patients we

Question

In a study of treatments for very painful "cluster" headaches, 140 patients were treated with oxygen and 153 other patients were given a placebo consisting of ordinary air. Among the 140 patients in the oxygen treatment group, 110 were free from headaches 15 minutes after treatment. Among the 153 patients given the placebo, 21 were free from headaches 15 minutes after treatment. Use a 0.05 significance level to test the claim that the oxygen treatment is effective. Complete parts (a) through (c) below. a. Test the claim using a hypothesis test. Consider the first sample to be the sample of patients treated with oxygen and the second sample to be the sample of patients given a placebo. What are the null and alternative hypotheses for the hypothesis test? H_0: p_1 = p_2 H_1: p_1 > p_2 H_0: p_1 greaterthanorequalto p_2 H_1: p_1 notequalto p_2 H_0: p_1 = p_2 H_1: p_1

Explanation / Answer

Here p1=x1/n1 = 110/140, p2= x2 /n2 =21/153 and p=(x1+x2) /(n1 +n2) =131/293.

The test statistic is,

z=( p1 - p2) /sqrt [p(1-p)(1/n1 +1/n2) =((110/140)-(21/153))/sqrt[(131/293)(1-(131/293))((1/140)+(1/153))]

=11.15 (Ans)

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.