Percent of Observations Above Mean plus Two Standard Deviations

C

95% of the observations lie between plus and minus two standard deviations from the mean. Therefore, 2.5% lie over and above two standard deviations on each side of the mean.

To answer this question, we need to understand the concept of the normal distribution and the empirical rule, also known as the 68-95-99.7 rule.

The empirical rule states that for a normal distribution:

• Approximately 68% of the observations fall within one standard deviation of the mean.
• Approximately 95% of the observations fall within two standard deviations of the mean.
• Approximately 99.7% of the observations fall within three standard deviations of the mean.

In this question, we are specifically interested in the observations that lie above the mean plus two standard deviations. According to the empirical rule, approximately 95% of the observations fall within this range.

Therefore, the correct answer is E. 95%.