Part A-
1. A company's customer support division want to test to see if that wait time for a consumer to talk to a representative is under 10 minutes. The manager proposes to test one case where a consumer was placed on hold. Is this a good testing strategy? If not what would be a better testing strategy? Could you form a Null Hypothesis or an Alternative Hypothesis? If yes, what would they be.
2. Using a specific example explain what a point estimation is and a confidence interval is.
Part B-
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?