A teacher has two large containers, A and B, filled with blue, red, and green beads. She wants her students to
estimate the difference (A - B) in the proportion of red beads in each container.
What is the appropriate inference procedure?
• two sample t-test for Ua - Ub
• two sample t-interval for Ua - Ub
• two sample z-test for Pa - Pb
• two sample z-interval for Pa - Pb