Hmm, (1 - (1-0.95))^9 also = 63%. No idea why 64, closest I can see is 1-(0.95)^20 or 1-(1-0.05)^20 = 64%.
Hmm, (1 - (1-0.95))^9 also = 63%. No idea why 64, closest I can see is 1-(0.95)^20 or 1-(1-0.05)^20 = 64%.