Distribution analysis (box plots) in Tableau - Cell-by-Cell Formula Trace

Sample Data

Sales amounts for 9 transactions used to analyze distribution with a box plot.

Cell	Value
A1	Sales
A2	200
A3	450
A4	300
A5	700
A6	150
A7	400
A8	600
A9	350
A10	500

Formula Trace

Calculate quartiles and whiskers for box plot: Q1, Median, Q3, Lower Whisker, Upper Whisker

Step 1: Sort Sales values: {150, 200, 300, 350, 400, 450, 500, 600, 700}

Step 2: Find Median (Q2): middle value of sorted list

Step 3: Find Q1: median of lower half {150, 200, 300, 350}

Step 4: Find Q3: median of upper half {450, 500, 600, 700}

Step 5: Calculate Interquartile Range (IQR): Q3 - Q1

Step 6: Calculate Lower Whisker: max(min value, Q1 - 1.5 * IQR)

Step 7: Calculate Upper Whisker: min(max value, Q3 + 1.5 * IQR)

Cell Reference Map

    A   
1 Sales 
2 200  
3 450  
4 300  
5 700  
6 150  
7 400  
8 600  
9 350  
10 500 

The formula uses all Sales values from A2 to A10 to calculate quartiles and whiskers.

Result

  Sales Distribution Box Plot Summary
-------------------------------------
Q1 (25th percentile): 250
Median (50th percentile): 400
Q3 (75th percentile): 550
Lower Whisker: 150
Upper Whisker: 700

This summary shows the key values used to draw the box plot representing the sales distribution.

Sheet Trace Quiz - 3 Questions

What is the median sales value in the dataset?

A 400

B 350

C 450

D 500

Key Result

Box plot calculation finds Q1, Median, Q3 from sorted data, then computes whiskers using 1.5*IQR rule.