The following building heights (in feet) are given: 50, 60, 55, 40, 45, 55, 55,...

To find the median value of the building heights, we first list the 18 values in ascending order: 40, 40, 45, 45, 45, 45, 50, 50, 50, 50, 55, 55, 55, 55, 55, 55, 60, 60. The median is the middle value in an ordered list. With 18 values (an even number), the median is the average of the 9th and 10th values. The 9th value is 50, and the 10th value is 50. Thus, the median is (50 + 50) / 2 = 50.0 ft., matching option A. Option B (50.5 ft.) might result from incorrect averaging. Option C (55.0 ft.) is the mode, not the median. Option D (56.9 ft.) appears to be the mean (total sum 910 / 18 ≈ 56.9), not the median. The APA’sAICP Certification Exam Content Outline(2022), under “Research and Assessment Methods,” includes basic statistical measures like the median, defined as “the middle value in an ordered dataset.” TheCPC Study Manual(2024) provides examples of median calculations, confirming this method.