This example uses data from Devore (1982, p335), which is based on data published in the Journal of Materials . There are 15 observations. The hypothesis is tested. The extremely large t value and the correspondingly small p -value provide strong evidence to reject the null hypothesis.
using System; using Imsl.Stat; public class NormOneSampleEx1 { public static void Main(String[] args) { double mean, stdev, lomean, upmean; int df; double t, pvalue; double[] x = new double[]{ 26.7, 25.8, 24.0, 24.9, 26.4, 25.9, 24.4, 21.7, 24.1, 25.9, 27.3, 26.9, 27.3, 24.8, 23.6}; /* Perform Analysis*/ NormOneSample n1samp = new NormOneSample(x); mean = n1samp.Mean; stdev = n1samp.StdDev; lomean = n1samp.LowerCIMean; upmean = n1samp.UpperCIMean; n1samp.TTestNull = 20.0; df = n1samp.TTestDF; t = n1samp.TTest; pvalue = n1samp.TTestP; /* Print results */ Console.Out.WriteLine("Sample Mean = " + mean); Console.Out.WriteLine("Sample Standard Deviation = " + stdev); Console.Out.WriteLine ("95% CI for the mean is " + lomean + " " + upmean); Console.Out.WriteLine("T Test results"); Console.Out.WriteLine("df = " + df); Console.Out.WriteLine("t = " + t); Console.Out.WriteLine("pvalue = " + pvalue); Console.Out.WriteLine(""); /* CI variance */ double ciLoVar = n1samp.LowerCIVariance; double ciUpVar = n1samp.UpperCIVariance; Console.Out.WriteLine ("CI variance is " + ciLoVar + " " + ciUpVar); /*chi-squared test */ df = n1samp.ChiSquaredTestDF; t = n1samp.ChiSquaredTest; pvalue = n1samp.ChiSquaredTestP; Console.Out.WriteLine("Chi-squared Test results"); Console.Out.WriteLine("Chi-squared df = " + df); Console.Out.WriteLine("Chi-squared t = " + t); Console.Out.WriteLine("Chi-squared pvalue = " + pvalue); } }
Sample Mean = 25.3133333333333 Sample Standard Deviation = 1.57881812336528 95% CI for the mean is 24.4390129997097 26.187653666957 T Test results df = 14 t = 13.0340861992294 pvalue = 3.21471738118362E-09 CI variance is 1.33609260499922 6.19986346723949 Chi-squared Test results Chi-squared df = 14 Chi-squared t = 34.8973333333333 Chi-squared pvalue = 0.0015223176141822Link to C# source.