Formula:

Lower Limit = m - t_0.975,n-1 x √((n+1)/n) x s.d
Upper Limit = m + t_0.975,n-1 x √((n+1)/n) x s.d
SDSRRL = s.d / 2
LlciLlrr = Llrr - t_0.975,n-1 x √((n+1)/n) x SDSRRL
UlciLlrr = Llrr + t_0.975,n-1 x √((n+1)/n) x SDSRRL
LlciUlrr = Ulrr - t_0.975,n-1 x √((n+1)/n) x SDSRRL
UlciUlrr = Ulrr + t_0.975,n-1 x √((n+1)/n) x SDSRRL


Where,
t - Distribution.
s.d - Standard Deviation
n - Total Count
m - Mean
LlciLlrr - is the Lower limit of the confidence interval of the Lower limit of the standard reference range
UlciLlrr - is the Upper limit of the confidence interval of the Lower limit of the standard reference range
LlciUlrr - is the Lower limit of the confidence interval of the Upper limit of the standard reference range
UlciUlrr - is the Upper limit of the confidence interval of the Upper limit of the standard reference range
SDSRRL - is the standard deviation of the standard reference range limit
Llrr - is the Lower limit of the standard reference range
Ulrr - is the Upper limit of the standard reference range

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