Using book debt-to-assets ratios only, estimate Rio Tintos levered equity beta based on the similar firm BHPs levered equity beta of 0.98 and BHP's book debt-to-assets ratio of 48%. State any necessary assumptions.

Price Data Time Series Sourced from Yahoo Finance Historical Price Data ASX200 Index (^AXJO) Rio Tinto (RIO.AX) Date Open High Low Close Adj Close Open High Low Close Adj Close 1/07/2017 5722 5800 5653 5721 5721 63.19 66.48 62.11 65.79 55.05 1/07/2018 6195 6306 6174 6280 6280 83.32 84.17 78.30 81.20 71.40 1/07/2019 6619 6876 6619 6813 6813 104.50 107.94 95.72 98.90 92.16 1/07/2020 5898 6161 5893 5928 5928 98.16 107.64 95.05 102.00 99.88 Price Data Time Series Sourced from Yahoo Finance Historical Price Data ASX200 Index (^AXJO) Rio Tinto (RIO.AX) Date Open High Low Close Adj Close Open High Low Close Adj Close 1/07/2017 5722 5800 5653 5721 5721 63.19 66.48 62.11 65.79 55.05 1/07/2018 6195 6306 6174 6280 6280 83.32 84.17 78.30 81.20 71.40 1/07/2019 6619 6876 6619 6813 6813 104.50 107.94 95.72 98.90 92.16 1/07/2020 5898 6161 5893 5928 5928 98.16 107.64 95.05 102.00 99.88