4. The following sample data are from a normal population: 20, 10, 8, 12, 15, 13, 11, 6, 5, 11 i. What is the point estimate of the population mean? [2] ii. What is the point estimate of the population standard deviation? [3] iii. With 95% confidence, what is the margin of error for the estimation of the population mean? iv. What is the 95% confidence interval for the population mean? [4] Interpret your results [1] [3]