Fix numbering sequence for Validation and A/B Testingsession and add 48. [A gentle and practical introduction to A/B tests](https://building.nubank.com.br/introduction-to-a-b-tests/)Nubank2022.
Thanks for this PR! Unfortunately, it's more of an introduction article rather than how A/B testing is done with a case study. Thus, we won't be merging this.
Fix numbering sequence for
Validation and A/B Testing
session and add48. [A gentle and practical introduction to A/B tests](https://building.nubank.com.br/introduction-to-a-b-tests/)
Nubank
2022
.