Return to the data you had generated in the second part of the Week Two assignment. You should have total numbers of first-born boys and girls in your state between the years 2007 and 2012 separately by racial group: American Indians or Alaska Natives, Asian or Pacific Islanders, Black or African Americans, and Whites. For the first part of this discussion, construct and report the 95% confidence intervals for the proportions of first-born boys, separately for each racial group. (Use the normal approximation to the binomial distribution.) Comment on the confidence intervals: can you infer from the confidence intervals that the proportions of first-born boys differ among the racial groups? Explain what the widths of the confidence intervals tell you.
Leading up to elections, you often hear results of polls of voters' preferences, with statements such as: "This poll was taken from a random sample of 600 potential voters, and has an accuracy exceeding 96%." Please interpret this statement in light of your knowledge of binomial confidence intervals. (Remember, the width of a confidence interval is a measure of the precision of the estimate.)