Miss. Code. tit. 11, pt. 8, ch. 2, app 11-8-2-A, 11-8-2-11-8-2-A-K
Rules 1,7,8
In this example, the permittee has taken an initial group of ten randomly located sampling circles. The results of this sampling are as follows:
| sampling circle no. (n) | countable trees/acre x | x2 |
| 1 | 7 | 49 |
| 2 | 10 | 100 |
| 3 | 4 | 16 |
| 4 | 5 | 25 |
| 5 | 10 | 100 |
| 6 | 11 | 121 |
| 7 | 3 | 9 |
| 8 | 7 | 49 |
| 9 | 10 | 100 |
| 10 | 10 | 100 |
| [SIGMA]x = 77 | [SIGMA](x2) = 669 |
now we need to calculate the variance, s 2
number of sampling circles (n) = 10
from the t table, we find t for a sample size of 10
n-1 = degrees of freedom
10-1 = 9 degrees of freedom for our example
from the t table, locate the t statistic for 9 degrees of freedom = 1.383
the sample adequacy formula is:
n = the number of samples which will need to be taken
t2 = t table value, squared
s2 = variance
plugging these values into the sample adequacy formula, we get:
Since we already have taken 10 samples and the sample adequacy formula tells us we need a total of 28, the sample adequacy requirements have not been met.
When the 18 additional samples have been taken, a new variance must be calculated and the sample adequacy formula recalculated. This is to ascertain that the additional samples didn't somehow increase the variance and, therefore, require still more samples. If this happens, the additional samples must be taken and the variance recalculated to determine sample adequacy.
In this example, it would have been wise to have taken an initial sample of 15 or 20. Whenever large variation is noted, initial sample size should be increased.
The sample adequacy requirements must be fulfilled before proceeding with comparison to the standard.
Miss. Code. tit. 11, pt. 8, ch. 2, app 11-8-2-A, 11-8-2-11-8-2-A-K