Python code to give the confidence interval for a one sample test. Uses z and t-distributions, without the need of look-up tables Data can be extracted any column in an ascii for csv files.
Can be run directly here
E.g. 30 data points ranging from 80740 to 117313.0, mean = 100200.37, SD = 11285.48 (pop) 11478.41 (samp)
Plot histogram [y/n]? n
Level of confidence [e.g. 95, 99, 99.9% - 3 sigma is 99.75]? 99
Sample size >= 30 so using z-value
For 99.00% confidence, z = 2.570, giving mean diff of 100200.37 +/- 5384.80 (94815.57 to 105585.17)
For two sample version see https://github.com/steviecurran/two-sample