Question 1: The length of human pregnancies from conception to birth varies according to a distribution that is approximately Normal with a mean of 266 days and standard deviation of 16 days.
- What percent of pregnancies last less than 240 days?
- What percent of pregnancies last between 240 days and 270 days?
- How long do the longest 20% of pregnancies last?
Question 2: A federal report find that a lie detector test given to truthful persons have a probability of 0.2 of suggesting that the person is deceptive. A company asks 12 job applicants to take a lie detect test. Suppose that all 12 applicants answer truthfully.
- What is the probability that exactly one is being deceptive.
- What is the probability that at most one is being deceptive.
- What is the mean and standard deviation of this distribution.