A researcher wishes to estimate, with 90% confidence, the population proportion

Question

A researcher wishes to estimate, with 90% confidence, the population proportion of adults who are confident wit he country's banking system. His estimate must be accurate within 2% of the proportion. (a) No preliminary estimate is available. Find the minimum sample size needed. (b) Find the minimum sample size needed, using a prior study that found that 28% of the respondents said they are confident with their country's banking system. (c) Compare the results from parts (a) and (b) (a) What is the minimum sample size needed assuming that no prior information is available? n = (Round up to the nearest whole number as needed).

Explanation / Answer

a) for no prior estimate p=0.5

for 90% CI, z=1.6449

margin of errror E =0.02

hence sample size =p(1-p)*(Z/E)2 =~1691 (rounding it up)

b) for p=0.28

sample size =p(1-p)*(Z/E)2 =~1364 (rounding it up)

c)in part A saqmple size is higher due to no estimation.

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

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