Statistical Functions
Beginner
AVERAGE with an Outlier
The mean is a fair summary only when nothing in the data is extreme.
Task:
You are quoting for next month and want to know what a typical job is worth. Put the average of the five invoices in B7, then look at how it compares to the invoices themselves.
Learning Objectives:
- Compute a mean over a range
- Notice when a single value dominates it
- See why an average on its own can mislead
Hints
Solve without hints for +5 XP
The data in this exercise
This is the grid you start with. Cell references in the task — B6, C2 — point at the row numbers and column letters below.
| A | B | |
|---|---|---|
| 1 | Job | Invoiced |
| 2 | Logo refresh | 450 |
| 3 | Brochure | 520 |
| 4 | Website copy | 480 |
| 5 | Packaging | 610 |
| 6 | Rebrand programme | 8400 |
| 7 | Average |
What this exercise teaches (contains the answer)
The average job is worth 2092, and four of the five jobs came in under 620. A single rebrand programme has dragged the mean past almost every real invoice, so quoting it would be indefensible. This is the failure the rest of this track exists to fix: MEDIAN, a few exercises from here, is what you reach for when one value is doing this.