# Civilize the Machine Essay

4763 WordsMay 6, 201320 Pages
Exam Three Material Read everything in the assigned chapters. You will be tested over the following concepts and passages. Entire passages are indicated by italics. Chapter Ten: The t Test for Independent Groups (Samples): What It Is and What It Does *The independent T-Test is a parametric statistical test that compares the means of two different samples of participants. It indicates whether the two samples perform similarly that we conclude that they are from the same population or that they perform differently that we conclude they are from two different populations. Statistical significance indicates that an observed difference between two descriptive statistics (Like means) is unlikely to have occurred by chance- this is why we use an independent-group t test. Calculations of independent Group t test= tobt=mean (Xbar)1- Mean (Xbar)2/SMean 1(Xbar)- Mean2(Xbar). The equation represents the standard error of the difference between means- the estimated standard deviation of the sampling distribution between the means of independent samples in a two sample experiment. Independent Group t Test determines how far the difference between the sample means fall from the difference between the population means. To determine how far the difference between the sample means is from the difference between the population means we convert the mean difference between the population means, and we convert the differences to standard errors. Insert formula- S(Xbar1-Xbar2)=square root S1square/n1 +S2square/nsquare) The mean of the distribution would be the difference between the means of the populations (Mean1-mean2), and its standard deviation would be (SXbar1-Xbar2) formula for tobt= Where tobt= Value of t obtained Xbar1 and X bar 2= means for the two groups S1square and s2square= variance of the two groups n1 and n2= number of participants in each of the two