up to, 1  as far as or approaching (a certain part, degree, point, etc.): She went wading up to her knees. I am up to the eighth lesson. 2  in full realization or attainment of: He worked up to president of the company. 3  as many as; to the limit of: The car will seat up to five persons.
The standard deviation is a measure of how the data is clustered about the mean. For large sets of data, approximately 68.3% of the data lies within one standard deviation of the mean and approximately 95.4% of the data lies within two standard deviations of the mean.
The standard deviation is a measure that indicates the extent to which the peaks and troughs of a wave differ on average from the mean voltage. A large standard deviation is a measure of large amplitude waves, i.e., on average the peaks and troughs differ by a large extent from the mean voltage.