Tо help mаke its speciаlty drinks fаster, JJ's Kоffee Klatch recently purchased a new high-quality espressо machine. Previously the average service time per customer was 90 seconds. The machine was installed 2 weeks ago, and a sample of 100 customers has shown an average service time of 80 seconds, with a standard deviation of 4 seconds. JJ wants to know if service time has decreased from the previous average service time of 90 seconds per customer. A budding, Lean Six Sigma Green Belt, JJ calculated a 95% confidence interval of (79.21, 80.79) on average service time. What conclusion should JJ make? [dec]