If the p-value is less than the significance level (commonly set at 0.05), you reject the null hypothesis, suggesting a statistically significant difference between the two group means. Since I cannot use the specific applet, I recommend using any statistical software or an online t-distribution calculator, entering the t-statistic (3.98) and df (21) to find the exact p-value. This will confirm whether the difference in means is statistically significant based on the conventional alpha level (e.g., 0.05)