In the Standard Normal Model, also known as the Gaussian distribution, the data is symmetrically distributed around its mean (which is 0). This model provides a way to understand how data is spread; the spread is measured in terms of standard deviations from the mean.
A large portion of the data falls within certain standard deviations from the mean. Specifically:
1. About 68.27% of the data falls within 1 standard deviation of the mean (both below and above).
To understand this, we need to remember that the Standard Normal Model adheres to the empirical rule (68-95-99.7 rule), which states:
- About 68% of the data falls within 1 standard deviation of the mean
- About 95% of the data falls within 2 standard deviations of the mean
- About 99.7% of the data falls within 3 standard deviations of the mean
Given this empirical rule and focusing on the percentage of data that falls within 1 standard deviation, we see that it is approximately 68.27%.
Therefore, the correct answer is approximately 68%.
So the most appropriate choice from the given options is:
68%.
