math
posted by bibi .
Empirical rule the authors generac generator produces voltage amounts with a mean of 125.0 volts and a standard deviation of 0.3 volt,and the voltage have a bellshape distribution.using the empirical rule,what is the approximate percentage of voltage amounts between 124.4 volts and 125.6 volts?

You are within two standard deviations. What is the rule?
http://davidmlane.com/hyperstat/z_table.html 
Empirical Rule