Question

6.3.20-T Question Help A researcher wishes to estimate, with 95% confidence, the population proportion of motor vehicle fatalities that were caused by alcohol-impaired driving. His estimate must be accurate within 2% of the population 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 36% of motor vehicle fatalities that were caused by alcohol-impaired driving. (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.) n B T Enter your answer in the answer box and then click Check Answer. 2 parts Clear All Check Answer remaining

Answer 1

n = 2401 b n = 2213 E- Wher ത estimate not given sample spre is mou.

To find required sample size when preliminarly estimate given or not a When estimate available formula No preliminary estimate [242] (0-25) n= F2 confidence level =95% 2012 -1.9600 2 na = 2% - (-1-9800) (0.25) E = 0.02 8 (0.03 G807 240) In=240) given P=0.36 P (1-P) (-1.96) 20-30 % (1-0.36) 2212 no E2 0.025 1) 0.8851 0.02)2 6.8851 0.0004 = 2212.75 - 2213