Determine the betas for the four securities by regressing each company's returns on the returns for the S&P/NZX50 Index (close) for the same period. The S&P/NZX50 index data can be obtained from https://finance.yahoo.com/quote/%5ENZ50/history?p=%5ENZ50. Explain what the values of the betas (the slope coefficients in the regression) indicate and discuss the factors that might explain the differences in the betas of the four companies. (6 marks) (Regression Calculation: Go to Data > Data Analysis and choose regression. The company returns constitute the Y input, and the index returns the X input. Alternatively, the "slope" found in f(x) also represents Beta. If Data Analysis does not appear, you can add the tool. It is available in Excel. Go to File > Options and choose Add-ins and go to Manage, then select click on the dropdown button and select Excel Add-ins, then click on Go. Select Analysis Toolpak and OK).