7. According to the U.S. Census Bureau, the number of people in a household has a mean of 2.G and a standard deviation of 1.5. Suppose the Census Bureau instead had estimated this mean using a random sample of 225 homes, and that sample loud a mean of 2.4 and standard deviation of 1.4. (a) Identify the variable y. [3 Points] (b) Describe the center and spread of the population distribution. [2 Points] (c) Describe the center and spread of the sample data distribution. (2 Points] (d) Describe the center and spread of the sampling distribution of the sample mean