I think you will find the reference of 1 to 7 is the market cap of each company.
Currently, IGO has a market cap of $7.38 billion. WSA has a market cap of $1.01 billion. For the purpose of rounding and fairness, Tomboy has suggested that the takeover bid would be based on a ratio of IGO having 7 times the market cap of WSA plus 20c cash being paid as part of the deal. That would give roughly one IGO share for about every 2.6 WSA shares held.
WSA Price at posting:
$3.13 Sentiment: Hold Disclosure: Held