Stats- Hypothesis test

Complete the following hypothesis test where σ is unknown

USA Today reported that the state with the longest mean life span is Hawaii, where the population mean life span is 77 years.  A random sample of 20 obituary notices in the Honolulu Advertizer had a mean of 71.4 years and a standard deviation, s = 20.65 yrs.  Assuming that life span in Honolulu is approximately normally distributed , does this information indicate that the population life span for Honolulu residents is less than 77 years?  Use a 5% level of significance