A cigarette manufacturer concerns that if the variance of the nicotine content of its cigarettes is more than 0.644. Actions for quality control are needed to be taken if their concern is true. Nicotine content is measured in milligrams, and assume that it is normally distributed. A random sample of 20 cigarettes has a standard deviation of 1.00 milligrams. IVl. State the formula of one unbiased estimator of the population variance. No proof needed. 2 points IV2. State most appropriate null and alternative hypotheses you would use to test if the manufacturer needs a modication of its facilities. 2 points IV-3. Find the rejection region (or decision rule) which could determine if there is any signicant (0: = 5%) evidence to suggest actions for quality control. [Answers without proper calculation and/ or justication will NOT get points] 4 points