With the information below. Assume no restrictions on short sales.

Variance-covariance matrix	W	X	Y	Z		Expected Return
W	0.1					3%
X	0.02	0.2				4%
Y	0.04	0.04	0.4			5%
Z	0.05	0.01	0.1	0.6		6%

a) Calculate the portfolio weights for the minimum risk premium portfolio using the four assets.

b) Identify five new efficient portfolios and use a table to report their portfolio weights, portfolio returns, and standard deviations. Draw an efficient frontier diagram on the plane of return-standard deviation, using the six efficient portfolios identified.

c) Assume a portfolio is composed of equal weights of each asset ([1/4, 1/4, 1/4, 1/4]). Is the portfolio efficient? Show with calculations.