Maths projects from Epitech
Description: Steven is a suit-seller in Mississippi. Once a year, he gets rid of his unsold stock, selling separately jackets and trousers, at $10, $20, $30, $40 and $50. He’d like to know how much each piece of clothing is likely to yield (expected value and variance).
Steven gave his statistician friend a mission: to deduce from his past results the probability to sell a $x jacket and $y trousers together. It appears that the probability is defined by the following formula (a and b being integers greater than 50, depending on the economic climate):
((a − x)(b − y)) / ((5a − 150)(5b − 150))
Let’s call X, Y and Z, respectively, the random variables that represent “the price of a sold jacket”, “the price of sold trousers” and “the price of a sold suit”. Given the values of a and b, your software must print:
• an array summing up the joint law of (X, Y ), and the marginal laws of X and Y ,
• an array summing up the law of Z,
• expected values and variances of X, Y and Z.