Pricing A/B Experiment Design Prompt

Design an A/B test for the pricing change below.
Specify:
- Primary metric and minimum detectable effect.
- Guardrail metrics (things that must not degrade).
- Required sample size (with assumed baseline conversion and power).
- Duration, and the traffic split.
- The one confound that would invalidate results.

Pricing change: {{change}}
Baseline conversion: {{baseline}}

Replace the {{fields}} with your own context and tighten the rules to match your domain.