Your portfolio consists of $90$ shares of CSH and $30$ shares of EJH, which you just bought at $$19\mathrm{.}09$ and $$29\mathrm{.}78$

per share, respectively.

a$.$ What fraction of your portfolio is invested in CSH$?$ In EJH?

b$.$ If CSH increases to $$21\mathrm{.}75$ and EJH decreases to $$27\mathrm{.}56,$ what is the return on your portfolio?