MATH 2565 Lecture Notes - Bernoulli Trial, Geom, Near-Sightedness

• School: York University
• Department: Mathematics and Statistics
• Course: MATH 2565
• Professor: Jagmohan Chawla

Document Summary

Problem 17. 17: coins and intuition: intuitively, we expect 50 heads, e(heads)= np = 100(0. 5) = 50 heads. There are only two possible outcomes, left-handed and not left-handed. Since people are selected at random, the probability of being left-handed is constant at about 13%. The trials are not independent, since the population is finite, but a sample of 5 people is certainly fewer than 10% of all people. Let x = the number of people checked until the first lefty is discovered. Let y = the number of lefties among n = 5: use. P(some lefties among the 5 people) = 1- p(no lefties among the first 5 people) P(first lefty is second or third person) = p(x = 2) + p(x = 3) = (0. 87)(0. 13) + (0. 87)2(0. 13) 0. 211: use binom (5,0. 13). P(exactly 3 lefties in the group) = p(y = 3) = 5.