Suppose a candidate running for sheriff claims that she will reduce the average speed of emergency response to less than 30 minutes. (30 minutes is thought to be the average response time with the current sheriff.) There are no past records, so the actual standard deviation of such response times cannot be determined. Thanks to this campaign, she is elected sheriff, and careful records are now kept. The response times for the first month are 26, 30, 28, 29, 25, 28, 32, 35, 24, 23 min. Using the .05 significance level, did she keep her promise?