(a) Suppose that stock A shares sell at $75 and stock B shares at $115. A portfolio has 300 shares of stock A and 100 of stock B. What are the weights w and 1 − w of stocks A and B in this portfolio?...

(a) Suppose that stock A shares sell at $75 and stock B shares at $115. A portfolio has 300 shares of stock A and 100 of stock B. What are the weights w and 1 − w of stocks A and B in this portfolio?

 (b) More generally, if a portfolio has N stocks, if the price per share of the jth stock is Pj , and if the portfolio has nj shares of stock j, then find a formula for wj as a function of n1,...,nN and P1,...,PN .