Answer:
By the Empirical Rule, [tex]\pm 3\sigma[/tex]
Step-by-step explanation:
The Empirical Rule states that, for a normally distributed random variable:
68% of the measures are within 1 standard deviation of the mean.
95% of the measures are within 2 standard deviation of the mean.
99.7% of the measures are within 3 standard deviations of the mean.
The symbol of a standard deviation is [tex]\sigma[/tex]. So
When plotting sample statistics on a control chart, 99.7% of the sample statistic values are expected to fall within plus/minus how many sigma?
By the Empirical Rule, [tex]\pm 3\sigma[/tex]
