Question

A research company conducts a poll in a particular geographical area asking adults 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). From a sample of 1800 ​people, results found 40​% of respondents considered themselves to be​ "thriving." Complete parts a and b below.

​a) Calculate the margin of error for the proportion of adults in this particular geographical area who were rated as​ "thriving" for 90​% confidence

b) Would the margin of error be larger or smaller for 85​%​ confidence? Choose one.

A. To be less ​confident, the interval needs to contain the true proportion less ​often, so the margin of error would be larger.

B. To be less ​confident, the interval needs to contain the true proportion more ​often, so the margin of error would be larger.

C. To be less confident, the interval needs to contain the true proportion less ​often, so the margin of error would be smaller.

D. To be less​ confident, the interval needs to contain the true proportion more​ often, so the margin of error would be smaller.

Answer 1