We have two test forms, X and Y, each with five items. Both tests are analyzed with the Rasch model. The items are numbered consecutively in the table below. We notice that two items, items 3 and 5, are common to X and Y.

Compute the estimated item parameters of the items of Y on the scale defined by test form X. Give the relationship between true scores for X and Y for θ = −4.0 (0.5) 4.0.