Final answer:
The three supplemental subtests of the WAIS-IV with age limits are Coding, Picture Completion, and Letter-Number Sequencing, which play a role in determining IQ and index scores.
Step-by-step explanation:
The three supplemental subtests in the WAIS-IV that have age limits are Coding, Picture Completion, and Letter-Number Sequencing. These subtests, along with others, contribute to an individual's performance across five indices: Verbal Comprehension, Visual Spatial, Fluid Reasoning, Working Memory, and Processing Speed.
When administering the WAIS-IV, it's important to know which subtests are suitable for what age ranges, as this can affect the accuracy of the assessment and ultimately, the IQ score and index scores that represent the test-taker's cognitive abilities.