9.11 A machine produces metal pieces that are cylin- drical in shape. A sample of pieces is taken, and the diameters are found to be 1.01, 0.97, 1.03, 1.04, 0.99, 0.98, 0.99, 1.01, and 1.03...

can you answer the 2nd problem with reference from the first problem

Extracted text: 9.11 A machine produces metal pieces that are cylin- drical in shape. A sample of pieces is taken, and the diameters are found to be 1.01, 0.97, 1.03, 1.04, 0.99, 0.98, 0.99, 1.01, and 1.03 centimeters. Find a 99% con- fidence interval for the mean diameter of pieces from this machine, assuming an approximately normal dis- tribution. 9.20 Consider the situation of Exercise 9.11. Esti- mation of the mean diameter, while important, is not nearly as important as trying to pin down the loca- tion of the majority of the distribution of diameters. Find the 95% tolerance limits that contain 95% of the diameters.