Please solve this and please be organized

Problem 4 [10 points = 5 + 5] Registrar's Ofce conducted a study of n = 9 test scores for randomly selected students. They assume that individual records are normally distributed with population standard deviation = a = 24 and unknown mean = u. Sample summaries are shown below Mean = X = 63.2 and Sample SD = s = 21 Set condence level 0' = 0.90 1. What critical value are you going to use for estimation of population mean ,u? 2. Show all elements of your interval, including mid-point, margin of error, and condence limits. You can leave answers in the form (UCL, LCL) = (MidPoint) :l: (Margin of Error) Solution