2. OSU virus induces a lethal fever in ducks. In order to determine the Cot1/2 of OSU DNA, a reassociation experiment was performed under standard conditions. The DNA concentration was 2 mM in nucleotides. Samples were removed at various times during the reaction and analyzed for the fraction of single-stranded DNA remaining. Due to an error (clumsy technician), only the sample taken at 45 min could be analyzed. The value for the fraction of single-stranded DNA (fss) was 0.1 in that sample. Calculate the Cot1/2 of OSU DNA.