question_answer 1)

Suppose that 90% of people are right-handed. What is the probability that at most 6 of a random sample 10 people are right handed ? 

Answer:

Let x is the number of right-handed people, then x has the binomial distribution with n = 10,             P(at most 6 people are right-handed)             = 1 ? [P (x = 7)+ P(x - 8) + P (x = 9) + P (x = 10)]