Question

what percentage of scores falls within 3 standard deviations of the mean? 95% 34% 99.7% 68%

Explanation:

Step1: Recall the empirical rule

The empirical rule (also known as the 68 - 95 - 99.7 rule) for a normal distribution states the percentage of data within 1, 2, and 3 standard deviations from the mean. For 3 standard deviations, the percentage is approximately 99.7%.

Step2: Match with the options

Among the given options (95%, 34%, 99.7%, 68%), the one corresponding to within 3 standard deviations is 99.7%.

Answer:

99% (Note: The correct value from the empirical rule is approximately 99.7%, and among the given options, 99.7% is the one that represents the percentage of scores within 3 standard deviations of the mean.)