Final answer:
To calculate the beta value for Portfolio i, we would need individual betas and investment proportions of Davies, Harris, Jones, and Roberts. The data provided is insufficient; thus, we're unable to determine the portfolio beta without further information.
Step-by-step explanation:
The question is asking to calculate the beta value for a portfolio, which includes investments in four different entities: Davies, Harris, Jones, and Roberts with respective investments of £1,500, £2,400, £700, and £400. The beta value is a measure of the volatility, or systematic risk, of a security or portfolio in comparison to the market as a whole. However, the provided information does not include the necessary data such as individual betas or the proportion of the total portfolio value that each investment represents. To calculate the portfolio beta, you would typically need the beta of each asset as well as the proportion of the total investment that each asset represents. Without this information or additional data, it is not possible to calculate the portfolio beta for portfolio i. Hence, to provide an exact answer, additional information regarding the market beta or the beta of individual investments is required.