The company Microtek manufactures switches with indicator light. A check is carried out regularly by taking a sample of 26 switches from production, each switch is checked and the number of non-compliant is noted. The results of the control of 280 samples of 26 switches each are summarized in the table below. a) Using these results, determine the average number of non-compliant switches per sample of size n = 26. (3 points) b) Give an estimate of the proportion of non-compliant switches per sample of size n=26. (3 points) c) Can we consider, at the significance level a = 0.01, that the variable "number of non-compliant switches in a sample of size n = 26" behaves according to a binomial law? (19 points)