If data are normal about 997 of the observations lie within

If data are normal, about 99.7% of the observations lie within three standard deviations of the mean. What percent lie within three standard deviations if the data are not normal? Round to three significant digits.

Solution

What percent lie within three standard deviations if the data are not normal?

it is not 99.7 %

it can be any value , it depends on what distribution is