A hard SQL interview practice problem on DataDriven. Write and execute real sql code with instant grading.

Domain

SQL

Difficulty

hard

Seniority

L4

Problem

For each experiment, show the number of users in control, the number in treatment, and the ratio of treatment to control. If an experiment has no control users, the ratio should be null.

Summary

Control versus treatment. The participation split.

Practice This Problem

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