Mason is an investor looking to build a balanced investment portfolio with a mix of renewable energy stocks and tech company shares. He aims to achieve a high return while managing the risk associated with market fluctuations. The following information summarises the key details of his investment choices:

Mason's investment portfolio consists of $$450,000$ in renewable energy stocks and $$300,000$ in tech company shares. The following details are associated with these stocks:

Renewable Energy Tech Company

Expected Return $12\%18\%$

Standard Deviation of Return $8\%15\%$

Correlation Coefficient $0\mathrm{.}65$

Required:

Calculate the portfolio's expected return and risk. $(6$ marks$)$