I have calculated the minimum inhibitory concentration (MIC)and got the mean and SD. The number of samples are 3, and I got mean and SD values. In all the groups I got SD zero (0) as there was no sampling error.
Now I would like to perform statistic to compare the mean of my samples with the standard. How will I compare as SD is zero?
Standard deviation (SD) of zero implies there is no dispersion and the data are exactly equal, which is not likely in a real-life scenario. If your data are not all equal the SD cannot be zero. Check your data again. They are not likely to be all equal and so SD is not likely to be zero.
Did you use computing software package to compute the statistical measures. I suggest you use computing software to avoid human error especially when the data set is large
The variance of a constant is zero. In your case the values are constant.
What response have you measured? (the variable for which you got three identical values within each group) And what are the (mean) values?
Hello, what do you mean by "numer of samples are 3"? Do you mean, you have several groups and 3 samples in each group? And are you computing mean and sd for the 3 samples of each group? I wonder how you "calculate" MIC. If your samples are alike, MIC should be the same. So I would also assume, your values are constant for each group. If not, the sd > 0.
If the variance shows zero and the data is not constant - check your rounding.... also, a sample of size 30 is sufficient to assume a normal sampling distribution... what is the sample size of the three samples? or is three in each group the total count?
statistics deals with variability so in this situation one can not apply statistical tools to such type of data.
- Badges
- Science topic
- Similar topics
- Mathematics
- Statistics