Here are the returns on two stocks.

$\backslash$table$[[,,$Digital,Executive$],[10,,$Cheese,Fruit$],[$points$,$January,$+14,+8],[,$February,$-4,+2],[,$March,$+6,+5],[$EBook$,$April,$+8,+12],[,$May,$-5,+3],[$Print$,$June,$+4,+6],[$References$,$July,$-3,-4],[,$August,$-9,-3]]$

Required:

Q$-1.$ Calculate the variance and standard deviation of each stock.

a$-2.$ Which stock is riskier if held on its own?

b$.$ Now calculate the returns in each month of a portfolio that invests an equal amount each month in the two stocks.

c$.$ Is the variance more or less than halfway between the variance of the two individual stocks?