The data in Table 1, which is Table T.1 in Cox & Snell's Applied Statistics, gives the intervals in service-hours between failures of the air-conditioning eequipment in 10 Boeing 720 jet aircraft. The following possible models are under consideration: (a) separate gamma distributions fitted to all aircraft, with 20 parameters; (b) separate gamma distributions with a common shape, with 11 parameters; (c) espearate exponential distributions to all aircraft (shape= 1, separate ?), with 10 parameters; (d) common exponential distribution to all aircraft (shape = 1), with 1 parameter. http://www.utstat.toronto.edu/reid/sta410/hw2.pdf I am having trouble in fitting gamma to the 10 different airplanes using only one shape parameter. Hopefully, somebody can suggest a way to specify the model to be used in R. I tried to join all 10 datasets into 1, but the estimate I get in gamma.shape() is not reasonable. Thank you