The waiting time for customers for MacBurger Restaurants follows a normal distribution with a population standard deviation is 1 minute. At the Warren Road MacBurger , the quality-assurance department sampled 50 customers and found that the mean waiting time was 2.75 minutes. At the 0.05 significance level, can we conclude that the mean waiting time is less than 3 minutes?

Compute the value of the test statistic