The inorganic mercury content in a single cigarette of a particular brand A is a random variable withmean 25 ng and a population standard deviation of 12 ng. A random sample of size 100 cigarettes is takenfor analysis.a) What is the approximate distribution of the sample mean? Explain briefly.b) The inorganic mercury content for a cigarette is considered high when the content is greaterthan 27 ng. What is the probability that the resulting sample mean content will be greater than 27 ng?c) Now suppose that the market analyst would like to test another brand B of cigarettes andselects a random sample of size of also 100 cigarettes from a population with mean inorganic mercurycontent 26 ng and a population standard deviation of 5 ng. What is the probability that the sample meancontent will be greater than 27 mg for this brand?d) Based on the above analysis of the sample means, which is a less harmful brand, A or B. Explain withnumbers. Would that also be true for individual cigarettes of the true brands?