1. Differentiate between a point estimate and an interval estimate for a population parameter.

2. What is necessary for an interval estimate to be a confidence interval?

3. What is meant when a sample statistic is said to be an unbiased estimator?

4. When calculating the sample variance, what procedure is necessary to ensure that s to the 2nd will be an unbiased estimator of o to the 2nd? Will s be an unbiased estimator of o?

5. During the month of July, an auto manufacturer gives its production employees a vacation period so it can tool
up for the new model run. In surveying a simple random sample of 200 production workers, the personnel director
finds that 38% of them plan to vacation out of state for at east one week during this period. Is this a point estimate
or an interval estimate? Explain.

6. A simple random sample of 8 employees is selected from a large firm. For the 8 employees, the number of
days each was absent during the past month was found to be 0, 2, 4, 2, 1, 7, 3, and 2, respectively.

a. What is the point estimate for u, the mean number of days absent for the firm's employees?

b. What is the point estimate for o to the 2nd, the variance of the number of days absent?