needing a breakdown of how to do 7 and 8 by hand.

7) A portfolio comprises Coke (beta of 1.3) and Wal-Mart (beta of 0.7). The amount invested in Coke is $20,000 and in Wal-Mart is $20,000. What is the beta of the portfolio? 7) @1.00 B) 0.9 C) 1.10 D) 0.95 8) A firm incurs $40,000 in interest expenses each year. If the tax rate of the firm is 30%, what is the effective after-tax interest rate expense for the firm? 8) $28,000.00 B) $22,400.00 C) $23,800.00