Final answer:
The normal distribution in question behaves according to the Empirical Rule, which states that about 68% of the data falls within one standard deviation of the mean in a bell-shaped, symmetric distribution. This percentage changes to about 95% within two standard deviations and over 99% within three standard deviations.
Step-by-step explanation:
A normal distribution in which approximately 68% of the data values fall within one standard deviation of the mean behaves according to the Empirical Rule. This is a key concept of descriptive statistics that applies specifically to bell-shaped, symmetric distributions. According to the rule, about 68 percent of the data lies within one standard deviation of the mean, about 95 percent lies within two standard deviations, and over 99 percent lies within three standard deviations.
For example, if a distribution has a mean (μ) of 50 and a standard deviation (σ) of 6, then approximately 68 percent of the values (x) would lie between 44 (50 - 6) and 56 (50 + 6). These points are one standard deviation away from the mean and correspond to the z-scores of -1 and +1, respectively. It is important to remember that this rule only applies when the distribution is perfectly bell-shaped and symmetric.