Question

Based on the Empirical rule, what percent of the observations will lie between plus or minus two standard deviations from the mean?

A. 2.5%
B. 95%
C. 68%
D. 5%

Answer 1

Based on the Empirical Rule, about 95% of observations are expected to be within two standard deviations from the mean in a bell-shaped and symmetric data distribution. Option B is the correct answer.

Step-by-step explanation:

Based on the Empirical Rule, which applies to data distributions that are bell-shaped and symmetrical, approximately 95% of the observations will lie within plus or minus two standard deviations from the mean.

This rule provides a quick way to evaluate the spread of data in a normal distribution, and is often referred to as the 68-95-99.7 rule. This is because according to the rule, about 68% of data falls within one standard deviation, 95% within two standard deviations, and 99.7% within three standard deviations of the mean.

Applying this rule to our question, the correct option is B. 95%.