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The mean water temperature downstream from a discharge pipe at a power plant cooling tower should be no more than 107 degrees F. Past experience has indicated that the population standard deviation of temperature is 6 degrees F. The water temperature is measured on 25 randomly chosen days, and the average temperature was found to be 99.1 degrees F.

What is the value of the test statistic for the appropriate hypothesis test for this problem? Round the final solution to two decimal places.