ion standard deviation of 12 ng. A random sample of n = 100 cigarettes is taken for analysis.

ion standard deviation of 12 ng. A random sample of n = 100 cigarettes is taken for analysis.

(2 points) What is the approximate distribution of the sample mean X ?

b) (2 points) The inorganic mercury content for a cigarette is considered high when the content is greater than 29 ng. What is the probability that the resulting sample mean content will be greater than 29 ng?

c) (2 points) Now suppose that the market analyst would like to test another brand of cigarettes and selects a random sample of n = 25 cigarettes from a population with mean inorganic mercury content 25 ng, but the standard deviation is now estimated from the sample as 10 ng. What is the probability that the sample mean content will be greater than 29 mg for this brand?