Table 1.

The best formula for estimation by distribution.

Best Formula for Sample size (n)	Mean Estimation		Standard Deviation Estimation
	Formula (5)	Median	Formula (16)	Range/4	Range/6
Log-Normal	n ≤ 23	23 <n	n ≤ 15	15 <n ≤ 64	64 <n
Beta	n ≤ 30	30 <n	n ≤ 15	15 <n ≤ 100	100 <n
Exponential	n ≤ 21	21 <n	n ≤ 15	15 <n ≤ 66	66 <n
Weibull	n ≤ 25	25 <n	n ≤ 16	16 <n ≤ 110	110 <n