. About 10% of people in the United States do not wear a seat belt. Suppose we take a random sample of 180 U. S. residents, and let X = the number of people who do not wear their seat belt. (a) Calculate the mean and standard deviation of the sampling distribution of X. (b) Interpret the standard deviation. (c) Justify that the distribution of X is approximately normal. (d) Use the normal distribution to calculate the probability that 26 or more individuals in the sample do not wear their seat belt.