Answer: 0.82
Explanation:
From the given formulas, the beta of Walmart is 0.3616 and the beta of Amazon is 1.1634.
The portfolio beta is going to be a weighted average of these two betas:
= (0.43 * 0.3616) + ( (1 - 0.43) * 1.1634)
= 0.155488 + 0.663138
= 0.82
