Q4 (8 points) Q4(8). Suppose that you are given a random sample (n = 18) of annual salaries for a specific position. The observed sample mean is x = $54,500. Assume population is normal with standard deviation = 9,500. 1(4) Find a 90% confidence interval for the true mean annual salary. 2(4) How large the sample size is necessary for the margin of error to be at most $3000? 1 + Drag and drop an image or PDF file or click to browse...