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1-2. The best estimate for the population mean would be sample mean of 60 gallons. Since we know that the sample mean is the best point of estimate. Since sample size n=16 is less than 25, we use the t distribution. Assume population from normal distribution.
3. Given a=0.1, the t (0.05, df = n – 1 = 15)=1.75
4. xbar ± t*s/vn = 60 ± 1.75*20/4 = ( 51.25, 68.75)
5. Since the interval include 63, it is reasonable.
