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                     Testing criteria:

                            If this test use significance level    and  the statistic t obtained from (T2)

                     or (T4), then

                     a. Testing criteria for the two-tailed test hypothesis (T1) as follows:

                           H0  is accepted if  t-actual    t/2-table , or

                           Pr = [ P ( t  -t actual ) + P ( t  t actual) ]    , otherwise


                           H0  is rejected if  t-actual  >  t/2-table ,    or

                           Pr = [ P ( t  -t actual ) + P ( t  t actual) ] <  .



                          To test whether the means of the first population is smaller than the mean

                     of second population, one-tailed test was used, with the following formulation of
                     the test hypothesis


                     b. Testing criteria for the one-tailed test hypothesis (T2) as follows:


                        H0  is accepted if   t -actual   - t-table   or   Pr ( Z  tactual )    , otherwise

                        H0  is rejected if  t -actual  < - t-tabel   or   Pr ( Z  tactual ) <   .


                     Worked Example  4.6 :

                          Data  on  the  test  scores  of  direct  and  cooperative  learning  models

                     successively recorded at columns 2 and 3 in Table 4.2. Test the hypothesis that

                     the two models of learning (a) did not differ, (b) the cooperative model is better

                     than the direct model.

                     Worked Solution :

                                           25                                   25
                                             X i                                X i
                     Means:          X   =    i= 1   =   1600  =  64                      X   =    i= 1   =   1918  =  76 . 72
                                       1
                                            25      25                      2    25      25





                                           ~~* CHAPTER 4   TESTING HYPOTHESIS *~~
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