Answer Happy

a) Let X denote the number of flaws observed on a large coil of galvanized steel. 75 coils are inspected and the following data were observed for the values of X. Does the assumption of a Poisson distribution seem appropriate as a probability model for this data? Use α=0.01. (12 marks) b) Four methods are under development for making discs of a superconducting material. 50 discs are made by each method and they are checked for superconductivity when cooled with liquid nitrogen. Use the 0.05 level of significance to test whether the proportions of superconductors are the same for the four methods.