What the values of the betas(the slope coefficients in the regression) indicate and discuss the factors that might explain the differences in the values of the betas of a trading companies, a company in the healthcare sector and a power generation company.

Beta coefficients of these three type of companies are below:

Trading companies
Company A	0.7226
Company B	0.7377
Healthcare Sector
Company C	0.4573
Power generation company
Company D	2.2784

Should Josh decide to invest in all the four companies in equal proportions? compute the return and risk of the portfolio.