According to an almanac, 70% of adult smokers started smoking before turning 18 years old.(a) Compute the mean and standard deviation of the random variable X, the number of smokers who started...

According to an almanac, 70% of adult smokers started smoking before turning 18 years old. (a) Compute the mean and standard deviation of the random variable X, the number of smokers who started smoking before 18 based on a random sample of 100 adults (b) Interpret the mean.