Final answer:
The statement that 95% of the data in a normal distribution falls within two standard deviations of the mean is true and is an aspect of the Empirical Rule applicable only to bell-shaped, symmetrical distributions.
Step-by-step explanation:
The statement in question is true. In a normal distribution, also known as a Gaussian distribution, approximately 95% of the data falls within two standard deviations of the mean. This is part of what is referred to as the Empirical Rule or the 68-95-99.7 rule, which describes the proportion of values that lie within each standard deviation for a normal distribution. Specifically, it states that about 68% falls within the first standard deviation, 95% within two standard deviations, and more than 99% within three standard deviations of the mean.It's crucial to recognize that these percentages hold true only for distributions that are bell-shaped and symmetric. If a dataset doesn't follow a normal distribution, the percentages will differ. This empirical observation is a foundational concept in statistics and is particularly useful when making inferences about a population based on sample data.