I believe the answer is: <span>no proven permanent method of disposal has yet been devised.
Since the halflive of nuclear substance is really long, disposing it by using the conventional method of disposal is deemed to be really dangerous for the environment around it. Currently, scientists are working to devise a perfect deep geological disposal for the nuclear material.</span>
Sample is a small set of number (n) represent whole population (N). Mean is the average of sample population (∑n/N). For Standard deviation subtract each number from mean and square it. Then find out the mean of squared differences and take square root of it.
<u>Explanation:</u>
Sample is the randomly chosen small set of number represented by n and it represents whole population (N). Sample mean is the average (n) observation from mean. Standard deviation is used to measure the deviation of data from the mean of the sample.
Sampling distribution provides a mean of statistical inference. Sample size should be large enough to represent the whole. It will be more statistically significant if it is large in size. Standard deviation is the dispersion or deviation of data set relative to its mean.
