(a) at the 5% significance level, the data provide convincing evidence of a real difference in the proportion who are not affected personally between americans who make less than $40,000 annually and americans who make $40,000 annually. (b) we are 95% confident that 16% more to 2% fewer americans who make less than $40,000 per year are not at all personally affected by the government shutdown compared to those who make $40,000 or more per year. (c) a 90% confidence interval for (p< 40k − p≥40k) would be wider than the (−0.16, 0.02) interval. (d) a 95% confidence interval for (p≥40k − p< 40k) is (-0.02, 0.16).