Consider the following data from a simple random sample of size n = 2 from a population of size N = 8, in which y is the variable of interest and x is an auxiliary variable: y1 = 50, x1 = 10; y2 = 22, x2 = 2. The population mean of the x's is 5. (a) Give the ratio estimate of the mean of the y-values. (b) Estimate the variance of the ratio estimator above.