A researcher wishes to estimate, with 99% confi accurate within 3% of the popula

Question

A researcher wishes to estimate, with 99% confi accurate within 3% of the population proportion (a) No preliminary estimate is available. Find the minimum sample size needed dence, the population proportion of adults who are confident with their country's banking system. His estimate must be Find the minimum sample size needed, (c) Compare the results from parts (a) and (b). (a) What is the minimum sample size needed assuming that no prior information is available? using a prior study that found that 22% of the respondents said they are confident with their country's banking system. (Round up to the nearest whole number as needed.) b what is the minimum sample size needed using a prior study that found that 22% of the respondents said they are confident with their country's banking system? (Round up to the nearest whole number as needed ) (c) How do the results from (a) and (b) compare? Having an estimate of the population proportion raises the minimum sample size needed. Having an estimate of the population proportion has no effect on the minimum sample size needed. O B. gth Click to select your answer(s). Save for Later TH1 Course Tools oopes Sample Tests and Quizzes 13 5

Explanation / Answer

(a) No preliminary estimate is available

let the estimate of p = 0.5

z value at 0.99/2 = 0.495 = 2.5758

Margin of error = 0.03/2 = 0.015

p(1-p) = 0.5*0.5 = 0.25

required sample size = (2.5758/0.015)2 *0.25 = 7372

(b) now p = 0.22

p(1-p) = 0.22*0.78 = 0.1716

required sample size = (2.5758/0.015)2 *0.1716 = 5060

(c) answer is option c i.e. having an estimate of the population proportion reduces the minimu samplesize needed

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

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