The management of White Industries is considering the new techniques of assembling its golf cart. The present method requires 42.3 minutes, on the average, to assemble a cart. The mean assembly time for a random sample of 24 carts, using the new method, was 40.6 minutes, and the standard deviation of the sample was 2.7 minutes.
The value of the test statistic is . (Negative amount should be indicated by a minus sign. Round your answer to 3 decimal places.)