An optical mark reader (OMR) is a machine that is able to “read” pencil marks that have been entered on a special form. A manufacturer of OMRs believes its product can operate equally well in a variety of temperature and humidity environments. To determine whether operating data contradict this belief, the manufacturer asks a well-known industrial testing laboratory to test its product. Five recently produced OMRs were randomly selected and each was operated in six different environments. The number of forms each was able to process in an hour was recorded and used as a measure of the OMR’s operating efficiency. These data appear in the table. Use the Friedman F_r test to determine whether evidence exists to indicate that the probability distributions for the number of forms processed per hour differ in location for at least two of the environments. Test using α = .10.

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OMR Machine Environment Number 1 2 4 5 6 8,001 8,025 8,100 8,055 7,991 8,007 2 7,910 7,932 7,900 7,990 7,892 7,922 8,111 8,101 8,201 8,175 8,102 8,235 4 7,802 7,820 7,904 7,850 7,819 8,100 5 7,500 7,601 7,702 7,633 7,600 7,561 1. N 3