Question

Alice knows that 70% of the creatures in Wonderland are anthropomorphic animals. She randomly invites several of Wonderland’s inhabitants to a tea party. Depending on which inhabitants of Wonderland are chosen, the proportion of animals invited may vary. If Alice samples 60 inhabitants, what is the probability that more than 65% of the sampled inhabitants are animals?

Give your answer to four decimal places.

Answer:______________

Answer 1

The population proportion is: p-0.70 The number of inhabitants is: n 60 Calculate the probability that more than 65% of the sampled inhabitants are animals. Here, the sample proportion is: p -0.65 P(p 065)-P Z» p(1- p -1- P Zs 0.65 -0.70 0.70(1-0.70) 60 -1-P(Z s-0.85) -1-(NORMSDIST-0.85)) (Use MS Excel function) 1-0.197663 0.802337 -0.8023 (Round to 4 decimal place) Hence, the required probability is 0.8023