The quality control manager would like to know whether the average daily production of the local chemical plant has changed in recent months. She randomly selects 51 days of production from the computer database and computes the average and its variance. The sample has an average of 803 tons and variance of 432 tons. The appropriate null hypothesis for this test is H_o : u = 836. What is the test statistics?

Write the answer with 2 decimal places.