$3.$Use the market model to estimate the beta for Colgate$-$Palmolive using the last $36$ months of returns $($the regression procedure in Excel is one easy way to do this$).$ Plot the monthly returns on Colgate$-$Palmolive against the index and also show the fitted line.

$\mathrm{.}4.$When the beta of a stock is calculated using monthly returns, there is a debate over the number of months that should be used in the calculation. Rework the previous questions using the last $60$ months of returns. How does this answer compare to what you calculated previously? What are some arguments for and against using shorter versus longer periods? Also, you$$ve used monthly data, which is a common choice. You could have used daily, weekly, quarterly, or even annual data. What do you think are the issues here?