1)

Suppose approximately75%of all marketing personnel are extroverts, whereas about50%of all computer programmers are introverts. (Round your answers to three decimal places.)

(a) At a meeting of 15 marketing personnel, what is the probability that 10 or more are extroverts?

What is the probability that 5 or more are extroverts?

What is the probability that all are extroverts?

(b) In a group of5computer programmers, what is the probability that none are introverts?

What is the probability that3or more are introverts?

What is the probability that all are introverts?

2)

Before 1918, approximately55%of the wolves in a region were male, and45%were female. However, cattle ranchers in this area have made a determined effort to exterminate wolves. From 1918 to the present, approximately70%of wolves in the region are male, and30%are female. Biologists suspect that male wolves are more likely than females to return to an area where the population has been greatly reduced. (Round your answers to three decimal places.)

(a) Before 1918, in a random sample of12wolves spotted in the region, what is the probability that9or more were male?

What is the probability that9or more were female?

What is the probability that fewer than6were female?

(b) For the period from 1918 to the present, in a random sample of12wolves spotted in the region, what is the probability that9or more were male?

What is the probability that9or more were female?

What is the probability that fewer than6were female?