A soft-drink machine at a steakhouse is regulated so that the amount of drink dispensed is normally distributed with a mean of 200 milliliters and a standard deviation of 15 milliliters. The soft-drink machine is checked by taking a sample of 9 drinks and computing the average amount of drink dispensed, which is 203 milliliters. The steakhouse manager is concerned that the amount of soft-drink dispensed is more than 200 milliliters. Use the 5% significance level. What is the test statistic for this hypothesis test?