10. Hypothesis Testing for Two Samples

Explain the difference between an independent and dependent sample.

"Public Cell Phone Conversations Researchers at Harris Interactive wondered if there was a difference between males and females in regard to some common annoyances. They asked a random sample of males and females, the following question: “Are you annoyed by people who repeatedly check their mobile phones while having an in-person conversation?” Among the 540 males surveyed, 178 responded “Yes”; among the 560 females surveyed, 206 responded “Yes.” Does the evidence suggest a higher proportion of females are annoyed by this behavior?Explain why this study can be analyzed using the methods for conducting a hypothesis test regarding two independent proportions.

d. Determine the P-value based on the model from part (c)."

"The Process of Statistics: Side Effects In clinical trials of the allergy medicine Clarinex (5 mg), 3307 allergy sufferers were randomly assigned to either a Clarinex group or a placebo group. It was reported that 50 out of 1655 individuals in the Clarinex group and 31 o

ut of 1652 individuals in the placebo group experienced dry mouth as a side effect of their respective treatments. Source: www.clarinex.com

e. Why is it important to have a placebo group?"

"[NW] Determining Sample Size A physical therapist wants to determine the difference in the proportion of men and women who participate in regular, sustained physical activity. What sample size should be obtained if she wishes the estimate to be within 3 percentage points with 95% confidence, assuming that

b. she does not use any prior estimates?"