Question 20 • Statistics
The observed difference in sample proportions is 0.4. The dotplot shows that a difference of 0.4 or more occurred in 7 of 200 simulated samples, or 7/200 = 0.035 (3.5%). Because this is a small proportion of the simulations, the result is statistically significant at the 5% level, giving convincing evidence that the new additive was more effective.
AI-written and checked against the verified answer.