Yesterday, the price of envelopes was $3 a box, and Julie was willing to buy 10 boxes. Today, the price has gone up to $3.75 a box, and Julie is now willing to buy only 8 boxes. Is Julie's demand for envelopes elastic or inelastic? What is Julie's elasticity of demand, using the midpoint formula? For higher revenue, would you recommend higher or lower price to the seller?