Question

Suppose that of all registered voters in a certain state favor banning the release of information from ect polls in presidential elections until after the poils in that state dose. A random sample of 25 registered voters is to be selected. Let x-number of registered voters in this random sample who favor the ban. (Use Table 9 in Appendix A. Round your answers to three decimal places) (a) What is the probability that more than 20 voters favor the ban? PX > 20) (b) What is the probability that at least 20 favor the ban? PLX 2 20) - What are the mean value and standard deviation of the number of voters who lavor the ban? Standard deviation

Answer 1

P=0.80, n=25 Binomial distribution a) P(x=2) = (b ) PR (1-P) P(x320) = 1 95-2 , °) ('using Binomiel [dishibution Gallery 51-0-5793 = 10:42077 25-2 5) P(XZzo) = 1-Ź 1895) (0-80)" (roso) = 1- 0.3833 = 10.6167 mean = np = 25X0.80 = 120 Ans Standard deviation = (hp (1-P) = 25X0-80 *(1-080) = 2 And