Suppose a population generally follows a normal curve, except that one of the measurements on this curve falls more than 3 standard deviations above the mean.What would you call this value?
A)An extreme outlier.
B)An error.All the values should lie within 3 standard deviations of the mean.
C)A value that has a 99.7% chance of occurring, because of the Empirical Rule.
D)None of the above.

Question

Quizplus · Accepted Answer

An extreme outlier is defined as a value that is more than 3 standard deviations from the mean. While it is unlikely to occur, it is still possible and is therefore not an error. The Empirical Rule states that approximately 99.7% of values will fall within 3 standard deviations of the mean, but does not apply to individual values.

Suppose a Population Generally Follows a Normal Curve, Except That