Question 4 (Mandatory) (1 point) Assume stock xyz has a beta of 1.5 and a residual standard deviation of 30%. The standard deviation of the market-index portfolio is 20%. An investor who currently holds the market-index portfolio decides to reduce the portfolio allocation to the market index to 90% and to invest 10% in stock xyz. What would have a greater impact on the new portfolio's standard deviation: an increase of 0.15 in xyz's beta or an increase of 3 percentage points (from 30 to 33%) in xyz's residual standard deviation? both would have the same impact the increase in its standard deviation can't be determined without knowing xyz's alpha the increase in its beta