Question

n= A researcher wishes to estimate, with 90% confidence, the population proportion of adults who support labeling legislation for genetically modified organisms (GMOs). Her estimate must be accurate within 5% of the true proportion a) No preliminary estimate is available. Find the minimum sample size needed () Find the minimum sample size nooded, using a prior study that found that 76% of the respondents said they support labeling legislation for GMOs (c) Compare the results from parts (a) and (b). (a) What is the minimum sample size needed assuming that no prior information is available? =(Round up to the nearest whole number as needed.) (b) What is the minimum sample size needed using a prior study that found that 76% of the respondents support labeling legislation? (Round up to the nearest whole number as needed.) (c) How do the results from (a) and (b) compare? O A. Having an estimate of the population proportion has no effect on the minimum sample size needed, O B. Having an estimate of the population proportion raises the minimum sample size needed. O C. Having an estimate of the population proportion reduces the minimum sample size needed.

Answer 1

Ans: Goren ME 5 do 0.05 for qo do Confidence, z = 20.1 = 1.645 Leb p=0.5 Ze 2 x P (1-0) 1.645 x 0,5x0,5 Sample size (n) = ME 2 0.052 270.6 & 271 n=271 -0.76 pe 1.645 x 0.76x (v-0.76) 2 n a 197.4 Z 197 0.052 In = 197 e) Havery an estimate of the population proportion reduces the monomom sample size needed. optoom @ Correct.