What does the empirical rule state about normal distributions?

The empirical rule, also known as the 68-95-99.7 rule, provides a succinct way to understand the distribution of values in a normal distribution. It states that approximately 68% of the data points fall within one standard deviation of the mean, about 95% fall within two standard deviations of the mean, and roughly 99.7% fall within three standard deviations of the mean. Therefore, the key points are:

• About 68% of the values lie between the mean and one standard deviation above or below the mean.
• Approximately 95% of the values are found within two standard deviations from the mean.

Given this understanding, the correct answer includes both statements regarding the percentages of values within one and two standard deviations. While the first statement is not accurate in terms of the characteristics of a normal distribution, the connection between one and two standard deviations accurately supports the claims made in the choices that involve the empirical rule. Therefore, validating the reasoning leads to the conclusion that both statements regarding approximately 70% and 95% of values reinforce the empirical rule's implications for normal distributions.