The data represented by the graph is normally distributed and adheres to the 68-95-99.7 rule. What is the standard deviation of this data?

The standard deviation of the data is 6.6.
Given the mean (μ) is 4.8. The graph shows two key points: -1.8 and 11.4. These are symmetric around the mean and likely represent one standard deviation below and above the mean, respectively, since the 68-95-99.7 rule is mentioned.
Therefore, the standard deviation of the data is 6.6.