A study compared the average memory recall scores of two groups: Group A (regular sleep schedule) and Group B (irregular sleep schedule). The results are presented in a bar graph, with error bars indicating the standard deviation for each group. The average score for Group A is 85 with an error bar extending from 80 to 90. The average score for Group B is 80 with an error bar extending from 75 to 85.
[Imagine a bar graph with two bars, Group A and Group B, with error bars as described.]
Based on the error bars shown, can it be concluded that there is a statistically significant difference in memory recall scores between Group A and Group B?
Correct: B
When comparing two groups using error bars representing standard deviation or standard error, if the error bars overlap significantly, it suggests that the observed difference between the means may not be statistically significant. In this case, Group A's error bar is 80-90, and Group B's error bar is 75-85. They overlap in the range of 80-85. This overlap indicates that, based on this representation, it is not possible to conclusively state a statistically significant difference between the two groups. More rigorous statistical tests would be needed to make such a conclusion.