Construct a 90% confidence interval for (p1−p2) in each of the following situations. a. n1=400;p^1=0.67;n2=400;p^2=0.55. b. n1=180;p^1=0.33;n2=250;p^2=0.24. c. n1=100;p^1=0.47;n2=120;p^2=0.61. a. The 90% confidence interval for (p1−p2) is ।, , ). (Round to the nearest thousandth as needed.)
