A randomized study compared the effectiveness of two mosquito repellents. The treatment group using Spray A reported a mean of 3.5 mosquito bites. The treatment group using Spray B reported a mean of 5.6 mosquito bites.

To determine if the results are significant, the data are re-randomized and the differences of the means are shown in the dot plot.

What is the best conclusion to make based on the data?