You run the following regression of Facebooks returns on the SP500 index over the prior 2 years

RFBRf=+(RS&PRf)+

You find that Facebooks beta equal 1.6. The weekly volatility of the residual from this regression is 0.03. And the R-squared of this regression is 0.33. What must have been the weekly volatility of SP500 excess returns over this time? Please provide your solution in decimal form, rounded to 3 decimal places. Only do the rounding of the final solution, keep all decimals in the intermediate stages of calculation (e.g., if the solution is 7.63% report 0.076)