10-5. Two machines are used to fill plastic bottles with
dishwashing detergent. The standard deviations of fill volume
are known to be o, = 0.10 fluid ounces and a, = 0.15 fluid ounces for the two machines, respectively. Two random sam-
ples of n, = 12 bottles from machine 1 and n2 = 10 bottles from machine 2 are selected, and the sample mean fill vol-
umes are 7, = 30.87 fluid ounces and #2 = 30.68 fluid
ounces. Assume normality.