Question

Approximately how much of the area under a standard curve is within one standard deviation of the mean?

99%


95%


68%


80%

Answer 1

Approximately 68% of the area under a standard normal distribution curve is within one standard deviation of the mean, also known as the 68-95-99.7 rule.

Specifically, the rule states that:

• Approximately 68% of the area under the curve falls within one standard deviation of the mean.
• Approximately 95% of the area under the curve falls within two standard deviations of the mean.
• Approximately 99.7% of the area under the curve falls within three standard deviations of the mean.

This means that if we have a normally distributed dataset with a mean of 0 and a standard deviation of 1, approximately 68% of the data points will fall within the range of -1 to +1 standard deviations from the mean.