A random survey of enrollment at 20 community colleges across the United States yielded the following gures: 21,921; 2,192; 9,414; 7,681; 3,200; 17,500; 9,200; 7,380; 18,314; 6,557; 13,713; 17,768; 7,493; 2,771; 2,861; 1,263; 7,285; 28,165; 5,080; 11,833. (a) Assume the underlying population is normal. i. it = Number ii. 8;; = Number iii. 71 = Number iv. n 1 = Number (d) Construct a 90% confidence interval for the population mean enrollment at community colleges in the United States. Enter your answer in interval notation. Round your answer to the nearest integer. Do not round any intermediate calculations