Confidence Intervals using the MATHEMATICA HypothesisTesting package

<<HypothesisTesting`

data = {2.2,4.3,1.7,6.6}

mean=Mean[data]

Compute a p - value for the population Mean to be significantly different from ZERO:

MeanTest[data,0]

Compute again the p - value as above, but assuming a known Variance of 9 :

MeanTest[data,0,KnownVariance->9]

When the variance is estimated from the population itself, the Student distribution is used :

MeanTest[data,0,FullReport->True]

Compute Confidence Intervals for the Mean, with different options for Variance and ConfidenceLevel:

MeanCI[data,KnownVariance->9,ConfidenceLevel->0.95]

MeanCI[data,ConfidenceLevel->0.95]

Compute a confidence interval for the Variance (default confidence level is .95) :

var=Variance[data]

VarianceCI[data]