A randomized study compared two drugs that are designed to increase a child's human growth hormone level. It was found that over a 1-year period, those receiving Drug A increased their hormone level by a mean of 28 IU. Those receiving Drug B increased their hormone level by a mean of 15 IU (IU = International unit). To determine whether the results are significant, the data are rerandomized and the difference of the means is shown in the dot plot. What is the best conclusion to make based on the data?