A letter in the December 1995 issue of Dell Champion Variety Puzzles stated: “I’ve noticed over the last several issues there have been no winners from the South in your contests. You always say that winners are picked at random, so does this mean you’re getting fewer entries from the South?” In response, the editors took a random sample of 1,000 entries from the last few contests, and found that 175 of those came from the South.
a. Find a 95% CI for the percentage of entries that come from the South.
b. According to Statistical Abstract of the United States, 30.9% of the U.S. population live in states that the editors considered to be in the South. Is there evidence from your CI that the percentage of entries from the South differs from the percentage of persons living in the South?