In March 2003, the Pew Research Group surveyed 1508 adult Americans and asked, “Do you believe the United States made the right or wrong decision to use military force in Iraq?” Of the 1508 adult Americans surveyed, 1086 stated the United States made the right decision. In August 2010, the Pew Research Group asked the same question of 1508 adult Americans and found that 618 believed the United States made the right decision.

(a) In the survey question, the choices “right” and “wrong” were randomly rotated. Why?

(b) Construct and interpret a 90% confidence interval for the difference between the two population proportions, p2003 - p2010.