I asked, “How’s life?” In the Gallup poll described in Exercise 2, 49% of those polled considered themselves to be “thriving.” a) Calculate the margin of error for the proportion of all American...

I asked, “How’s life?” In the Gallup poll described in Exercise 2, 49% of those polled considered themselves to be “thriving.”

a) Calculate the margin of error for the proportion of all American adults who were rated as “thriving” for 99% confidence.

 b) Would the margin of error be larger or smaller for 95% confidence? Explain. Section 4

Exercise 2

How’s life? Gallup regularly conducts a poll asking people to imagine a ladder with 10 rungs. Rung 0 represents the worst possible life and rung 10 represents the best possible life. Respondents are asked what rung they would say they are on. Responses are classified as “Thriving” (standing on rung 7 or higher, and expecting to be on rung 8 or higher five years from now), “Suffering” (standing on rung 4 or lower and expecting to be on rung 4 or lower 5 years from now), or “Struggling” (not thriving or suffering). The poll for November 22–25, 2011, found 4% of respondents to be suffering. The polls all use a sample size of approximately 1500 people. (www.gallup.com/poll/152033/Fewer-Americans-Thriving-2011-2010.aspx)

 a) Explain the meaning of “pn = 0.04” in the context of this situation.

 b) Calculate the standard error of pn.

 c) Explain what this standard error means in the context of this situation.