Number 1: The serum cholesterol levels of a population of 12 to 14 year olds follow a normal distribution with mean 162mg/dl and standard deviation 28 mg/dl. a) What percentage of 12 to 14 years olds...

Extracted text: Number 1: The serum cholesterol levels of a population of 12 to 14 year olds follow a normal distribution with mean 162mg/dl and standard deviation 28 mg/dl. a) What percentage of 12 to 14 years olds have serum cholesterol between 152 and 172 mg/dl? b) Suppose we are to choose at random from the population of large number of groups of nine 12 to 14 years old each. In what percentage of the groups the group mean cholesterol value would be between 152 and 172 mg/dl? c) If Y represents the mean cholesterol value of a random sample of nine 12 to 14 year from the population, what is Pr(152 < ỹ=""><>