We assume that the number of people entering a store follows a Poisson distribution with parameter \(\lambda \). Every customer spends money in the store, independently of each other according to a uniform distribution on \([10,100]\). We observe \(X\), the total amount of money spent in the store on a given day.
(a) Estimate \(\lambda \) using the method of moments.
(b) Let assume that we have the stores income \(X_1,X_2,\ldots ,X_n\) for \(n\) days and \(X_1,X_2,\ldots ,X_n\) are independent and distributed as \(X\). What would be the moment estimator for \(\lambda \) based on \(X_1,X_2,\ldots ,X_n\)?