A machine is producing metal pieces that are cylindrical
in shape. A sample of 12 pieces is taken and the diameters are:
1.01, 0.97, 1.03, 1.04, 0.8, 0.78, 1.06, 0.95, 0.87,1.0,0.88 and
0.90 centimeters.
a. Find 98% confidence interval for the true average diameter of
metal pieces produced by the machine.
We would like to test whether the true average diameter
of metal pieces produced by the machine is less than 1
centimeter.
b. Assuming the population distribution is approximately...