The questionable claim
A dashboard compares all April with May 1–10 and announces falling monthly sales.
Investigate
Identify the unit of analysis, denominator, population or information boundary. What extra evidence would be needed? Write a corrected statement first.
Diagnosis and repair
Compare equal elapsed windows or clearly mark partial periods. A projection needs stated assumptions; it is not an observed full-month result.
Prevention
Add a test or review question that catches the error before publication. Save the original and corrected explanation so your reasoning is auditable.
Make the reasoning yours.
Try the activity before reading its reference. Keep your sources, commands and assumptions with your work. Companion activities are unsaved self-practice and do not award a certificate or change lesson progress.