To find the sample variance, use technology or either formula shown below, where x 1 comma x 2 comma ... comma x Subscript n are the n observations in the sample and x overbar is the sample mean. s squared equals StartStartFraction Summation from nothing to nothing x Subscript i Superscript 2 Baseline minus StartFraction left parenthesis Summation from nothing to nothing x Subscript i Baseline right parenthesis squared Over n EndFraction OverOver n minus 1 EndEndFraction or s squared equals StartFraction Summation from nothing to nothing left parenthesis x Subscript i Baseline minus x overbar right parenthesis squared Over n minus 1 EndFraction