EmailBoost, a digital marketing agency, launched an A/B test on its latest email campaign to evaluate the effectiveness of a new subject line. The goal was to determine if the new subject line significantly increased the click-through rate (CTR) compared to the original.
| Group | Sample Size | Clicks | Click-Through Rate |
|---|---|---|---|
| Control (original subject line) | 50,000 | 6,000 | 12.0% |
| Treatment (new subject line) | 30,000 | 4,800 | 16.0% |
Determine whether the observed 4.0 percentage point increase in CTR is statistically significant.