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2. Harmonic average a) What is the harmonic mean of 2,5 , and 8 ? b) You have a portfolio of two stocks in which 25% is invested in stock AB and 75% in stock CD. The price-to earnings ratio (P/E) for stock AB is 18 whereas the price-to earnings ratio (P/E) for stock CD is 75 . i) What is the P/E ratio for the portfolio using the weighted arithmetic average? ii) What is the P/E ratio for the portfolio using the harmonic average