Page 63 - Basic Statistics
P. 63

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                     Worked Solution:

                            Given                :      = 15; n = 25
                                                    0
                                                  And   x = 18 . 32; s = 15.845

                     (a). Test hypothesis       :   H :   = 15;
                                                    0
                                                        0
                                                  H  :    15
                                                         0
                                                    1
                     Significance level         :      = 0.05

                     The critical value        :   t =  t    =  2.064
                                                         ; 2 /  24

                                                  (at the t-table, with  (25-1) degrees of freedom)

                                                                s    15 . 845
                     Standard deviation for  X   :       s  =      =         = 3.169
                                                          x
                                                                n      ( 25 )

                                                              X −       18 . 32 − 15
                                                         t =         0   =
                                                                 s x         . 3  169

                                                                       = 1.05


                     Test results :  t    < t    , 2 /  db= n− 1 , ie 1.05 < 2.064, then H is accepted or not enough
                                                                             0
                     evidence to reject H . It was concluded that the average absences of workers in
                                          0

                     one year is equal to 15 days.




                     b. Test hypothesis        :    H :    = 15
                                                        0
                                                    0
                                                  H  :    > 15
                                                         0
                                                    1
                     Significance level        :      = 0.05

                     The critical value        :   t =  t  =  ……..
                                                       
                     Test  results  :  ………………..,ie…………...,  then  H   is……………..  It  was
                                                                               0
                     concluded that ………………………..








                                           ~~* CHAPTER 4   HYPOTHESIS TESTING *~~
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