The owner of a local nightclub has recently surveyed a random sample of n = 250 customers of the club. she would now like to determine whether or not the mean age of her customers is over 30. if so, she plans to alter the entertainment to appeal to an older crowd. if not, no entertainment changes will be made. suppose she found that the sample mean was 30.45 years and the sample standard deviation was 5 years. if she wants to be 99% confident in her decision, what decision should she make?