A restaurant claims that the standard deviation in the length of serving

A restaurant claims that the standard deviation in the length of serving times is less than 2.9 minutes.  A disgruntled customer believes that the standard deviation is more than 2.9 minutes.  He takes a random sample of 23 serving times, which has a standard deviation of 3.3 minutes.  At α = 0.10, is there enough evidence to support the customer’s claim?  Assume the population is normally distributed.