Standard Deviation Calculator for Frequency Table: Values, Counts, Mean, Variance, and SD

Calculate standard deviation from a frequency table by entering each value repeated by its count, then use the calculator results for sample or population SD, variance, mean, standard error, range, z-score, and confidence interval workflows. Built for QC engineers analyzing 20-100 batch SPC measurements, instructors summarizing score counts, and analysts converting discrete frequency tables into report-ready statistics.