One sample t-test
Use the one sample t-test to test whether the average of observations differs significantly from a test value.
Logarithmic transformation: if the data require a logarithmic transformation (e.g. when the data are positively skewed), select the Logarithmic transformation option.
The results window first displays the summary statistics of the observations.
The One sample t-test panel shows:
If the calculated P-value is less than 0.05, the conclusion is that, statistically, the sample mean is significantly different from the test value.
If you selected the Log transformation option, the program performs the calculations on the logarithms of the observations, but reports the back-transformed summary statistics.
For the One sample t-test, the difference between sample mean and test value, with 95% confidence interval, are given on the log-transformed scale.
Next, the results are transformed back and the interpretation is as follows: the back-transformed difference of the logs is ratio of the sample mean / test value on the original scale.