2 One-Sample ProblemA sample of 12 radon detectors of a certain type was selected, and each was exposed to 100 pCi/L of radon. The resulting readings were as follows:105.6, 90.9, 91.2, 96.9, 96.5, 91.3, 100.1, 105.0, 99.6, 107.7, 103.3, 92.4Problem: To test that the population mean reading is 100, and to construct a confidence interval for this population mean.Summary: n = 12, Xbar = , S =
3 Two-Sample ProblemThe deterioration of many municipal pipeline networks across the country is a growing concern. One technology proposed for pipeline rehabilitation uses a flexible liner threaded through existing pipe. The following data represents the tensile strength (psi) of liner specimens for when a certain fusion process was used and when this process was not used.The study intended to show that using the fusion process increased the mean tensile strength.
7 Problems to Demonstrate Testing Equality of Population Means Using T-TestConfidence Interval for the Difference of Population MeansTesting Equality of Population VariancesConfidence Interval for the Ratio of Population Variances
8 Testing Equality of Means (Equal Variances) Two Sample T-Test and Confidence IntervalTwo sample T for NoFusion vs FusedN Mean StDev SE MeanNoFusionFused95% CI for mu NoFusion - mu Fused: ( -455, 45)T-Test mu NoFusion = mu Fused (vs <): T = P = DF = 16Both use Pooled StDev = 249
9 Testing Equality and CI of Means (Unequal Variances) Two Sample T-Test and Confidence IntervalTwo sample T for NoFusion vs FusedN Mean StDev SE MeanNoFusionFused95% CI for mu NoFusion - mu Fused: ( -448, 38)T-Test mu NoFusion = mu Fused (vs <): T = P = DF = 15