Stats 2.7Case study6 parts

Project Lab: Audit a Business Claim

Reproduce, diagnose and rewrite a misleading but realistic statistical claim from a chart and its underlying data.

In this lesson6 parts

  1. 01Recreate the constructed slide faithfully
  2. 02Count what the slide actually shows
  3. 03Build the missing denominator
  4. 04Inspect missing IDs and the source's reach
  5. 05Repair the display and assemble the audit
  6. 06Reproduce and hand off the report

Key terms

The words this lesson introduces, each in one line. The module’s glossary collects them all.

unit of analysis
The entity counted once for the stated result: one gross positive invoice.
declared filter
An explicit rule selecting rows for a calculation.
percentage change
Difference divided by the starting value, expressed per hundred: 21.57% for 255 to 310.
truncated axis
An axis whose shown range starts above the quantity's zero point, here a constructed floor of 240.
rate denominator
The group total used beneath the numerator for a stated comparison: that week's distinct active identified customers.
missing identifier
A recorded event whose entity link is absent: an invoice with no customer ID.
time window
The exact interval of records included in a comparison.

Quiz 5 questions

Your first pick on each question is the one that counts, and a right one earns a coin. Getting one wrong here is how the lesson sticks.

Practice

Problems to solve in your own notebook. Each states the problem, not the steps: working out the steps is the exercise. Level A applies the lesson, B combines it with earlier ones, C stretches it.

The self-checking notebook for this lesson is Stats 2.1, 2.2 and 2.7 · EDA and a chart audit.

Common mistakes

What you will see when it goes wrong, why it happens, and the fix.

Where it’s used

Where this lesson’s ideas turn up in real work.