5.56. The skull breadths of a certain population of rodents follow anormal distr
ID: 2914513 • Letter: 5
Question
5.56.
The skull breadths of a certain population of rodents follow anormal distribution with a standard deviation of 10mm. Let Y be the mean skull breadth of a random sample of 64individuals from this population, and let be the populationmean skull breadth.
(a) Suppose = 50 mm. Find Pr {Y is within ± 2mm of }
(b) Suppose = 100 mm. Find Pr {Y is within± 2mm of }
(c) Suppose is unknown. Can you find Pr {Yis within ± 2mm of }? If so, do it. If not explain, whynot.