In a standard normal distribution, the empirical rule (also known as the 68-95-99.7 rule) is a key principle that helps us understand the spread of data around the mean. According to the empirical rule:
1. Approximately 68% of the data falls within ±1 standard deviation of the mean.
2. Approximately 95% of the data falls within ±2 standard deviations of the mean.
3. Approximately 99.7% of the data falls within ±3 standard deviations of the mean.
In this case, we are interested in the range where 95% of the data lies within. According to the empirical rule, 95% of the data in a standard normal distribution is within ±2 standard deviations of the mean.
Therefore, the correct answer is 2.
