5 30 first-year students at EKU who regularly play video games had an average GPA of 2.84 after the first semester . We are interested in a 90% confidence interval for the mean GPA of EKU students who regualry play video games. What is the appropriate critical value? O z* = 1.645 O t* = 1.699 O t* = 1.664 O t* = 1.684