The amount of coffee that people drink per day is normally distributed with a mean of 15 ounces and a standard deviation of 4 ounces. 18 randomly selected people are surveyed. Round all answers to 4 decimal places where possible. a. What is the distribution of X? X - N( b. What is the distribution of D? I ~ N( c. What is the probability that one randomly selected person drinks between 13.5 and 16 ounces of coffee per day? d. For the 18 people, find the probability that the average coffee consumption is between 13.5 and 16 ounces of coffee per day. e. For part d), is the assumption that the distribution is normal necessary? O Yes No f. Find the IQR for the average of 18 coffee drinkers. Q1 = ounces Q3 = ounces IOR: ounces