Answer: 0.34
Explanation:
Gillette’s advertising elasticity tells of the impact that Gillette's advertising has on its demand.
Given the details in the question, the following formula can be used;
Advertising elasticity/ -Gillette elasticity of demand = Gillette’s advertising-to-sales
Advertising elasticity/ -(-4.5) = 7.5%
Advertising elasticity = 7.5% * 4.5
= 0.34